diff --git a/app/controllers/calendar/single.php b/app/controllers/calendar/single.php
index 48c04da68c569c4393799340d853acfb7527e44f..e2ea4c7e9d2bf4e1489606c28007740a6eb0c4c1 100644
--- a/app/controllers/calendar/single.php
+++ b/app/controllers/calendar/single.php
@@ -197,7 +197,8 @@ class Calendar_SingleController extends Calendar_CalendarController
         $calendar = new SingleCalendar($this->range_id);
         $event = $calendar->getEvent($event_id);
         if (!$event->isNew()) {
-            $export = new CalendarExportFile(new CalendarWriterICalendar());
+            $calender_writer = new CalendarWriterICalendar();
+            $export = new CalendarExportFile($calender_writer);
             $export->exportFromObjects($event);
             $export->sendFile();
         }
@@ -210,7 +211,8 @@ class Calendar_SingleController extends Calendar_CalendarController
         $this->calendar = new SingleCalendar($this->range_id);
 
         if (Request::submitted('export')) {
-            $export = new CalendarExportFile(new CalendarWriterICalendar());
+            $calender_writer = new CalendarWriterICalendar();
+            $export = new CalendarExportFile($calender_writer);
             if (Request::get('event_type') == 'user') {
                 $types = ['CalendarEvent'];
             } else if (Request::get('event_type') == 'course') {
@@ -245,8 +247,8 @@ class Calendar_SingleController extends Calendar_CalendarController
         if ($this->calendar->havePermission(Calendar::PERMISSION_OWN)) {
             if (Request::submitted('import')) {
                 CSRFProtection::verifySecurityToken();
-                $import = new CalendarImportFile(new CalendarParserICalendar(),
-                        $_FILES['importfile']);
+                $calender_parser = new CalendarParserICalendar();
+                $import = new CalendarImportFile($calender_parser, $_FILES['importfile']);
                 if (Request::get('import_as_private_imp')) {
                     $import->changePublicToPrivate();
                 }
diff --git a/app/controllers/course/enrolment.php b/app/controllers/course/enrolment.php
index 89145226edc0e33871689c76e0de5c90bde1337f..16038ff6acb95287f20e1f8e6430f4cca2ae57d3 100644
--- a/app/controllers/course/enrolment.php
+++ b/app/controllers/course/enrolment.php
@@ -46,7 +46,7 @@ class Course_EnrolmentController extends AuthenticatedController
             (in_array($enrolment_info['cause'], words('root courseadmin member'))
                 || ($enrolment_info['cause'] == 'free_access' && $GLOBALS['user']->id == 'nobody'))
         ) {
-            $redirect_url = UrlHelper::getUrl('seminar_main.php', ['auswahl' => $this->course_id]);
+            $redirect_url = URLHelper::getUrl('seminar_main.php', ['auswahl' => $this->course_id]);
             if (Request::isXhr()) {
                 $this->response->add_header('X-Location', $redirect_url);
                 $this->render_nothing();
diff --git a/app/controllers/course/lvgselector.php b/app/controllers/course/lvgselector.php
index 9624c70b45f5f40b9374b3a3ebadfdafafda2d68..6fcb6580266e5f7919249508487455362ca9d722 100644
--- a/app/controllers/course/lvgselector.php
+++ b/app/controllers/course/lvgselector.php
@@ -276,9 +276,9 @@ class Course_LvgselectorController extends AuthenticatedController
         if ($this->is_locked($course_id)) {
             throw new AccessDeniedException();
         }
-        
+
         $lv_group_ids = $selection->getLvgruppenIDs();
-        
+
         // check whether at least one lv-group or study area is required
         $study_areas_combined_enabled = CourseWizardStepRegistry::findOneBySQL("
                 `classname` = 'StudyAreasLVGroupsCombinedWizardStep'
@@ -291,7 +291,7 @@ class Course_LvgselectorController extends AuthenticatedController
             }
         }
         // write the new lvgruppen to the db
-        LvGruppe::setLvgruppen($course_id, $lv_group_ids);
+        Lvgruppe::setLvgruppen($course_id, $lv_group_ids);
         PageLayout::postMessage(MessageBox::success(_('Die Zuordnung der LV-Gruppen wurde übernommen.')));
     }
 
diff --git a/app/controllers/course/studygroup.php b/app/controllers/course/studygroup.php
index d2d347819bc985cb5aea7dcf08472a15e38acbf1..bdf43de5b443d5959c160c56abd9960d68e9932d 100644
--- a/app/controllers/course/studygroup.php
+++ b/app/controllers/course/studygroup.php
@@ -775,7 +775,7 @@ class Course_StudygroupController extends AuthenticatedController
             // save invite in database
             StudygroupModel::inviteMember($receiver, $id);
             // send invite message to user
-            $msg     = new Messaging();
+            $msg     = new messaging();
             $sem     = new Seminar($id);
             $message = sprintf(_("%s möchte Sie auf die Studiengruppe %s aufmerksam machen. Klicken Sie auf den untenstehenden Link, um direkt zur Studiengruppe zu gelangen.\n\n %s"),
                 get_fullname(), $sem->name, URLHelper::getlink("dispatch.php/course/studygroup/details/" . $id, ['cid' => null]));
@@ -795,7 +795,7 @@ class Course_StudygroupController extends AuthenticatedController
                 $addedUsers
             ));
         } else if ($count >= 1) {
-            pageLayout::postSuccess(sprintf(
+            PageLayout::postSuccess(sprintf(
                 _('%s wurden in die Studiengruppe eingeladen.'),
                 $addedUsers
             ));
diff --git a/app/controllers/ical.php b/app/controllers/ical.php
index 06afc4d36cd8064798b19f1fc4b414b10ba48890..4ecdc13755fdef584fbb38a7c5739b2d744347c3 100644
--- a/app/controllers/ical.php
+++ b/app/controllers/ical.php
@@ -52,7 +52,8 @@ class iCalController extends StudipController
             $GLOBALS['perm'] = new Seminar_Perm();
 
             $extype = 'ALL_EVENTS';
-            $export = new CalendarExport(new CalendarWriterICalendar());
+            $calender_writer = new CalendarWriterICalendar();
+            $export = new CalendarExport($calender_writer);
             $export->exportFromDatabase($user_id, strtotime('-4 week'), 2114377200, 'ALL_EVENTS');
 
             if ($GLOBALS['_calendar_error']->getMaxStatus(ErrorHandler::ERROR_CRITICAL)) {
diff --git a/app/controllers/messages.php b/app/controllers/messages.php
index dc0de21a66f51efbb0f7597517587c23753ff0df..836c4bd27b11d195a29a3301af0ba521fc906477 100644
--- a/app/controllers/messages.php
+++ b/app/controllers/messages.php
@@ -943,7 +943,7 @@ class MessagesController extends AuthenticatedController {
     public function delete_tag_action()
     {
         CSRFProtection::verifyUnsafeRequest();
-        DbManager::get()->execute("DELETE FROM message_tags WHERE user_id=? AND tag LIKE ?", [$GLOBALS['user']->id, Request::get('tag')]);
+        DBManager::get()->execute("DELETE FROM message_tags WHERE user_id=? AND tag LIKE ?", [$GLOBALS['user']->id, Request::get('tag')]);
         PageLayout::postMessage(MessageBox::success(_('Schlagwort gelöscht!')));
         $this->redirect('messages/overview');
     }
diff --git a/app/controllers/oer/mymaterial.php b/app/controllers/oer/mymaterial.php
index 6f6f4c3cf111df8fafe2552ccb0843361c450a7a..bcabeacfa2459dbdd0f070181712837e4bac5f4f 100755
--- a/app/controllers/oer/mymaterial.php
+++ b/app/controllers/oer/mymaterial.php
@@ -21,7 +21,7 @@ class Oer_MymaterialController extends AuthenticatedController
 
     public function edit_action(OERMaterial $material = null)
     {
-        Pagelayout::setTitle($material->isNew() ? _('Neues Material hochladen') : _('Material bearbeiten'));
+        PageLayout::setTitle($material->isNew() ? _('Neues Material hochladen') : _('Material bearbeiten'));
         if ($material->id && !$material->isMine() && !$GLOBALS['perm']->have_perm('root')) {
             throw new AccessDeniedException();
         }
@@ -198,7 +198,7 @@ class Oer_MymaterialController extends AuthenticatedController
 
     public function statistics_action(OERMaterial $material)
     {
-        Pagelayout::setTitle(sprintf(
+        PageLayout::setTitle(sprintf(
             _('Zugriffszahlen für %s'),
             $material->name
         ));
diff --git a/app/controllers/studiengaenge/informationen.php b/app/controllers/studiengaenge/informationen.php
index 0515f879610d0eb07d4b7b7016d13d565550bf50..4bbdd019a958cec71694219eebb4f0cb8431f7f6 100644
--- a/app/controllers/studiengaenge/informationen.php
+++ b/app/controllers/studiengaenge/informationen.php
@@ -1,7 +1,7 @@
 <?php
 /**
  * @author      Peter Thienel <thienel@data-quest.de>
- * @author      
+ * @author
  * @license     GPL2 or any later version
  * @since       4.6
  */
@@ -11,7 +11,7 @@ class Studiengaenge_InformationenController extends MVVController
     public function before_filter(&$action, &$args)
     {
         parent::before_filter($action, $args);
-        
+
         if (!($GLOBALS['perm']->have_perm('root') || RolePersistence::isAssignedRole(
                         $GLOBALS['user']->id, 'MVVAdmin'))) {
             throw new AccessDeniedException();
@@ -21,7 +21,7 @@ class Studiengaenge_InformationenController extends MVVController
             Navigation::activateItem('mvv/studiengaenge/informationen');
         }
     }
-    
+
     public function index_action()
     {
         $this->createSidebar();
@@ -38,13 +38,13 @@ class Studiengaenge_InformationenController extends MVVController
             [':inst_ids' => $inst_ids]);
         }
     }
-    
+
     public function degree_action ()
     {
         $this->createSidebar('degrees');
         $this->degree = Degree::findBySQL('abschluss_id IN (SELECT DISTINCT(abschluss_id) FROM user_studiengang) ORDER BY name');
     }
-    
+
     public function showdegree_action($studycourse_id, $nr = 0)
     {
         $this->studycourse = Fach::find($studycourse_id);
@@ -55,7 +55,7 @@ class Studiengaenge_InformationenController extends MVVController
                 ['studycourse_id' => $studycourse_id,
                  'abschluss_ids' => $this->studycourse->degrees->pluck('abschluss_id')]);
     }
-    
+
     public function showstudycourse_action($degree_id, $nr = 0)
     {
         $this->nr = $nr;
@@ -75,7 +75,7 @@ class Studiengaenge_InformationenController extends MVVController
             [':inst_ids' => $inst_ids]);
         }
     }
-    
+
     public function messagehelper_action()
     {
         $fach_id = Request::get('fach_id');
@@ -96,7 +96,7 @@ class Studiengaenge_InformationenController extends MVVController
                 [':abschluss_id' => $degree_id]);
         }
         if (empty($user)) {
-            Pagelayout::postError(_('Keine Studierenden zu den gewählten Angaben gefunden'));
+            PageLayout::postError(_('Keine Studierenden zu den gewählten Angaben gefunden'));
             $this->redirect('index');
             return;
         }
@@ -114,7 +114,7 @@ class Studiengaenge_InformationenController extends MVVController
             ['default_subject' => $subject, 'emailrequest' => 1]
         ));
     }
-    
+
     private function createSidebar($view = 'subject' )
     {
         $widget = new ViewsWidget();
@@ -124,7 +124,7 @@ class Studiengaenge_InformationenController extends MVVController
                 ->setActive($view == 'degrees');
         Sidebar::Get()->addWidget($widget);
     }
-    
+
     public static function getStudyCount($degree_id)
     {
         if ($GLOBALS['perm']->have_perm('root', $GLOBALS['user']->id)) {
@@ -142,5 +142,5 @@ class Studiengaenge_InformationenController extends MVVController
 
         }
     }
-    
+
 }
\ No newline at end of file
diff --git a/app/routes/Events.php b/app/routes/Events.php
index 7ad0f1bc79eced6921107ad1b55b19ef94a3745b..38caa14bcb3bdfa7da90f40d897aa0c1b26054c8 100644
--- a/app/routes/Events.php
+++ b/app/routes/Events.php
@@ -83,8 +83,8 @@ class Events extends \RESTAPI\RouteMap
         if ($user_id !== $GLOBALS['user']->id) {
             $this->error(401);
         }
-
-        $export = new CalendarExport(new CalendarWriterICalendar());
+        $calender_writer = new CalendarWriterICalendar();
+        $export = new CalendarExport($calender_writer);
         $export->exportFromDatabase($user_id, 0, 2114377200, 'ALL_EVENTS');
 
         if ($GLOBALS['_calendar_error']->getMaxStatus(\ErrorHandler::ERROR_CRITICAL)) {
diff --git a/app/views/blubber/compose.php b/app/views/blubber/compose.php
index e23487a072a0ca601a7c4b54e93010dc37757cfb..23b1c217db54aa9473f92b963c106a3897690ee2 100644
--- a/app/views/blubber/compose.php
+++ b/app/views/blubber/compose.php
@@ -48,7 +48,7 @@
             <span class="container">
                 <select name="user_ids[]" class="select2" id="blubber_contacts" multiple>
                     <? foreach ($contacts as $contact) : ?>
-                        <option value="<?= htmlReady($contact['user_id']) ?>" data-avatar="<?= htmlReady(Avatar::getAvatar($contact['user_id'])->getImageTag(AVATAR::SMALL)) ?>">
+                        <option value="<?= htmlReady($contact['user_id']) ?>" data-avatar="<?= htmlReady(Avatar::getAvatar($contact['user_id'])->getImageTag(Avatar::SMALL)) ?>">
                             <?= htmlReady($contact->friend->getFullName()) ?>
                         </option>
                     <? endforeach ?>
diff --git a/app/views/my_studygroups/_course.php b/app/views/my_studygroups/_course.php
index e3855c4c33b17ef6a29da9f1f4a846acd80113c5..fc3ca414134f7c8d8721deacc347a45658058502 100644
--- a/app/views/my_studygroups/_course.php
+++ b/app/views/my_studygroups/_course.php
@@ -27,7 +27,7 @@
                 <? foreach (MyRealmModel::array_rtrim($group['navigation']) as $key => $nav)  : ?>
                     <? if (isset($nav) && $nav->isVisible(true)) : ?>
                         <a href="<?=
-                        UrlHelper::getLink('seminar_main.php',
+                        URLHelper::getLink('seminar_main.php',
                             ['auswahl'     => $group['seminar_id'],
                                   'redirect_to' => strtr($nav->getURL(), '?', '&')]) ?>" <?= $nav->hasBadgeNumber() ? 'class="badge" data-badge-number="' . intval($nav->getBadgeNumber()) . '"' : '' ?>>
                             <?= $nav->getImage()->asImg(20, $nav->getLinkAttributes()) ?>
diff --git a/app/views/studiengaenge/studiengaenge/stgteil_bezeichnungen.php b/app/views/studiengaenge/studiengaenge/stgteil_bezeichnungen.php
index fe943d63c9c3a1a1f6bbddeb988b851b567067e2..5955182964348ddcf4e580387334ef8cdfcf4ec7 100644
--- a/app/views/studiengaenge/studiengaenge/stgteil_bezeichnungen.php
+++ b/app/views/studiengaenge/studiengaenge/stgteil_bezeichnungen.php
@@ -27,7 +27,7 @@
                 <? endif; ?>
             </tbody>
         <? endforeach; ?>
-        <? if ($studiengang->typ === 'mehrfach' && MvvPerm::haveFieldPermStudiengangteil($studiengang, MVVPerm::PERM_CREATE)) : ?>
+        <? if ($studiengang->typ === 'mehrfach' && MvvPerm::haveFieldPermStudiengangteil($studiengang, MvvPerm::PERM_CREATE)) : ?>
             <tfoot>
                 <tr>
                     <td colspan="3">
diff --git a/app/views/studiengaenge/studiengaenge/studiengangteile.php b/app/views/studiengaenge/studiengaenge/studiengangteile.php
index ed0aa0593823e16d8d3d33d14a1167ce4ad21142..1e044b6392ac9ad2271bd2c072f105bb49ef3b5b 100644
--- a/app/views/studiengaenge/studiengaenge/studiengangteile.php
+++ b/app/views/studiengaenge/studiengaenge/studiengangteile.php
@@ -5,11 +5,11 @@
             <col width="1%">
         </colgroup>
         <? foreach ($stgteile as $stgteil) : ?>
-            <tbody id="<?= $stg_stgbez_id . '_' . $stgteil->id ?>"<?= MvvPerm::haveFieldPermStudiengangteil($studiengang, MVVPerm::PERM_WRITE) ? 'class="sort_items"' : '' ?>>
+            <tbody id="<?= $stg_stgbez_id . '_' . $stgteil->id ?>"<?= MvvPerm::haveFieldPermStudiengangteil($studiengang, MvvPerm::PERM_WRITE) ? 'class="sort_items"' : '' ?>>
                 <tr class="header-row">
                     <td width="90%"><?= htmlReady($stgteil->getDisplayName()) ?></td>
                     <td class="actions">
-                        <? if (MvvPerm::haveFieldPermStudiengangteil($studiengang, MVVPerm::PERM_CREATE)) : ?>
+                        <? if (MvvPerm::haveFieldPermStudiengangteil($studiengang, MvvPerm::PERM_CREATE)) : ?>
                             <? if ($stg_bez) : ?>
                                 <? $msg = sprintf(
                                         _('Wollen Sie die Zuordnung des Studiengangteils "%s" als "%s" zum Studiengang "%s" wirklich löschen?'),
@@ -47,7 +47,7 @@
                 </tr>
             </tbody>
         <? endforeach; ?>
-        <? if (MvvPerm::haveFieldPermStudiengangteil($studiengang, MVVPerm::PERM_CREATE)) : ?>
+        <? if (MvvPerm::haveFieldPermStudiengangteil($studiengang, MvvPerm::PERM_CREATE)) : ?>
             <tfoot>
                 <tr>
                     <td colspan="2">
diff --git a/db/migrations/1.155_tic_5170_clean_up.php b/db/migrations/1.155_tic_5170_clean_up.php
index 7030ead322cebdccd2f0e6138a659fbe3593040c..950da2ef0b0ed8939370d89392748b580249dd6e 100644
--- a/db/migrations/1.155_tic_5170_clean_up.php
+++ b/db/migrations/1.155_tic_5170_clean_up.php
@@ -8,7 +8,7 @@ class Tic5170CleanUp extends Migration
 
     public function up()
     {
-        $db = DbManager::get();
+        $db = DBManager::get();
         $db->exec("ALTER TABLE `message` DROP `chat_id`, DROP `readed`");
         $db->exec("ALTER TABLE `message_user` DROP `confirmed_read`");
         try {
diff --git a/db/migrations/1.156_tic_5204_add_datafield_type.php b/db/migrations/1.156_tic_5204_add_datafield_type.php
index 951288ae15002d8665eba92f95f4f95098a31d41..ba6ad7249229b1e704f1f35fa093eca7bb9db39f 100644
--- a/db/migrations/1.156_tic_5204_add_datafield_type.php
+++ b/db/migrations/1.156_tic_5204_add_datafield_type.php
@@ -8,7 +8,7 @@ class Tic5204AddDatafieldType extends Migration
 
     public function up()
     {
-        $db = DbManager::get();
+        $db = DBManager::get();
         $db->exec("ALTER TABLE `datafields` CHANGE `type` `type` ENUM('bool','textline','textarea','selectbox','date','time','email','phone','radio','combo','link','selectboxmultiple') NOT NULL DEFAULT 'textline'");
         $db->exec("ALTER TABLE `datafields` ADD `is_userfilter` TINYINT UNSIGNED NOT NULL DEFAULT '0' AFTER `is_required`");
     }
diff --git a/lib/calendar/CalendarWriterICalendar.class.php b/lib/calendar/CalendarWriterICalendar.class.php
index fdc32b3ff6015e147d60e3b98637286dc9333e9a..b416dde82e9b86374190df17f13956f32da60a99 100644
--- a/lib/calendar/CalendarWriterICalendar.class.php
+++ b/lib/calendar/CalendarWriterICalendar.class.php
@@ -18,7 +18,7 @@
 
 define('CALENDAR_WEEKSTART', 'MO');
 
-class CalendarWriteriCalendar extends CalendarWriter
+class CalendarWriterICalendar extends CalendarWriter
 {
     var $newline = "\r\n";
 
diff --git a/lib/classes/FilesSearch/Result.php b/lib/classes/FilesSearch/Result.php
index c4cfb1f13b96a79a2cb8db6184b2d67b0a0cf491..c989105cbb48956deaac04d4b5ff067c6abf88ad 100644
--- a/lib/classes/FilesSearch/Result.php
+++ b/lib/classes/FilesSearch/Result.php
@@ -345,11 +345,11 @@ class Result
     private function getOrderBy()
     {
         switch ($this->query->getSort()) {
-            case QUERY::SORT_CHDATE:
+            case Query::SORT_CHDATE:
                 $orderBy = 'ORDER BY fsa.file_ref_mkdate DESC';
                 break;
 
-            case QUERY::SORT_RELEVANCE:
+            case Query::SORT_RELEVANCE:
                 $orderBy = 'ORDER BY sr.ranking DESC';
                 break;
 
diff --git a/lib/classes/ForumAbo.php b/lib/classes/ForumAbo.php
index fa84a487284755deed182bced4bd57e0da6140bf..b057ae79571df2e0fbe67447ed5ddf7ad4733dbb 100644
--- a/lib/classes/ForumAbo.php
+++ b/lib/classes/ForumAbo.php
@@ -78,7 +78,6 @@ class ForumAbo
         // send message to all abo-users
         $db = DBManager::get();
         $messaging = new ForumBulkMail();
-        // $messaging = new Messaging();
 
         // get all parent topic-ids, to find out which users to notify
         $path = ForumEntry::getPathToPosting($topic_id);
diff --git a/lib/classes/JsonApi/Routes/Events/UserEventsIcal.php b/lib/classes/JsonApi/Routes/Events/UserEventsIcal.php
index 364474ec6e69acaeb5c10a877fe2410805d53854..335f90556a98e6c7e0b6276361df09216eba9275 100644
--- a/lib/classes/JsonApi/Routes/Events/UserEventsIcal.php
+++ b/lib/classes/JsonApi/Routes/Events/UserEventsIcal.php
@@ -23,8 +23,8 @@ class UserEventsIcal extends NonJsonApiController
             // damit unsichtbare Nutzer nicht ermittelt werden können
             throw new RecordNotFoundException();
         }
-
-        $export = new \CalendarExport(new \CalendarWriterICalendar());
+        $calender_writer = new \CalendarWriterICalendar();
+        $export = new \CalendarExport($calender_writer);
         $export->exportFromDatabase($observedUser->id, 0, 2114377200, ['CalendarEvent', 'CourseEvent', 'CourseCancelledEvent']);
         if ($GLOBALS['_calendar_error']->getMaxStatus(\ErrorHandler::ERROR_CRITICAL)) {
             throw new InternalServerError();
diff --git a/lib/classes/JsonApi/Routes/Events/UserEventsIndex.php b/lib/classes/JsonApi/Routes/Events/UserEventsIndex.php
index 567f9aecdc8582c0e55c2452d6c1413c4cc597bd..353382bb687b3668abccb29e01c85e5447fe02ce 100644
--- a/lib/classes/JsonApi/Routes/Events/UserEventsIndex.php
+++ b/lib/classes/JsonApi/Routes/Events/UserEventsIndex.php
@@ -18,9 +18,6 @@ class UserEventsIndex extends JsonApiController
 
     public function __invoke(Request $request, Response $response, $args)
     {
-        require_once 'lib/calendar/CalendarExportFile.class.php';
-        require_once 'lib/calendar/CalendarWriterICalendar.class.php';
-
         if (!$observedUser = \User::find($args['id'])) {
             throw new RecordNotFoundException();
         }
diff --git a/lib/classes/ModulesNotification.class.php b/lib/classes/ModulesNotification.class.php
index a8be148a6dedda89940b96ffb0eb4b14669e245e..ae86645f1c63366ef2cb3df1caed51ab65daa651 100644
--- a/lib/classes/ModulesNotification.class.php
+++ b/lib/classes/ModulesNotification.class.php
@@ -149,7 +149,7 @@ class ModulesNotification
     function getPluginText($nav, $seminar_id, $id)
     {
         $base_url = URLHelper::setBaseURL('');
-        UrlHelper::setBaseURl($base_url);
+        URLHelper::setBaseURl($base_url);
         if ($nav instanceof Navigation && $nav->isVisible(true)) {
                 $url = 'seminar_main.php?again=yes&auswahl=' . $seminar_id . '&redirect_to=' . strtr($nav->getURL(), '?', '&');
                 $icon = $nav->getImage();
diff --git a/lib/classes/SemBrowse.class.php b/lib/classes/SemBrowse.class.php
index fd4b2dc320ee0b3a9f059198601511a20743c2dc..ef6136c5df04dbdc822807a10ddfaf42db4c98b6 100644
--- a/lib/classes/SemBrowse.class.php
+++ b/lib/classes/SemBrowse.class.php
@@ -887,7 +887,7 @@ class SemBrowse {
 
             }
             $send_from_search = URLHelper::getUrl(basename($_SERVER['PHP_SELF']), ['keep_result_set' => 1, 'cid' => null]);
-            $send_from_search_link = UrlHelper::getLink($this->target_url,
+            $send_from_search_link = URLHelper::getLink($this->target_url,
                     [
                         $this->target_id => $seminar_id,
                         'cid' => null,
@@ -984,7 +984,7 @@ class SemBrowse {
                             $row .= '... <a href="' . $send_from_search_link . '">(' . _('mehr') . ')</a>';
                             break;
                         }
-                        $row .= '<a href="' . UrlHelper::getLink('dispatch.php/profile', ['username' => $doz_uname[$index]]) . '">' . htmlReady($value) . '</a>';
+                        $row .= '<a href="' . URLHelper::getLink('dispatch.php/profile', ['username' => $doz_uname[$index]]) . '">' . htmlReady($value) . '</a>';
                         if ($i != count($doz_name) - 1) {
                             $row .= ', ';
                         }
diff --git a/lib/classes/StudygroupModel.php b/lib/classes/StudygroupModel.php
index 23930c04fc09240aaf5fba8f46d56c7ae4730db9..be4575e9cc5852f1e45200eacc9fef0925371dc1 100644
--- a/lib/classes/StudygroupModel.php
+++ b/lib/classes/StudygroupModel.php
@@ -552,7 +552,7 @@ class StudygroupModel
         $dozenten   = $sem->getMembers();
         $tutors     = $sem->getMembers('tutor');
         $recipients = [];
-        $msging     = new Messaging();
+        $msging     = new messaging();
 
         foreach (array_merge($dozenten, $tutors) as $uid => $user) {
             $recipients[] = $user['username'];
diff --git a/lib/classes/admission/CourseSet.class.php b/lib/classes/admission/CourseSet.class.php
index cf6cac788933d6cc3122965f6f22443bf4514800..3ea4997183cd8ad504a1ac35041e755cab487701 100644
--- a/lib/classes/admission/CourseSet.class.php
+++ b/lib/classes/admission/CourseSet.class.php
@@ -247,7 +247,7 @@ class CourseSet
     {
         NotificationCenter::postNotification('CourseSetAlgorithmWillStart', $state, $this->getId());
         $this->hasAlgorithmRun = (bool)$state;
-        $db = DbManager::get();
+        $db = DBManager::get();
         $ok = $db->execute("UPDATE coursesets SET algorithm_run = ? WHERE set_id = ?", [$this->hasAlgorithmRun, $this->getId()]);
         if ($ok) {
             NotificationCenter::postNotification('CourseSetAlgorithmDidStart', $state, $this->getId());
diff --git a/lib/classes/admission/RandomAlgorithm.class.php b/lib/classes/admission/RandomAlgorithm.class.php
index 3d9866194c9b9e642c63a69455116ce46d319096..c0fa3f0b6f57388116ac0b5f2c2280a6c713f2e5 100644
--- a/lib/classes/admission/RandomAlgorithm.class.php
+++ b/lib/classes/admission/RandomAlgorithm.class.php
@@ -425,7 +425,7 @@ class RandomAlgorithm extends AdmissionAlgorithm
         $sum = function($r) use (&$distributed_users) {
             $distributed_users[$r['user_id']] += $r['c'];
         };
-        $db = DbManager::get();
+        $db = DBManager::get();
         $db->fetchAll("SELECT user_id, COUNT(*) as c FROM seminar_user
             WHERE seminar_id IN(?) AND user_id IN(?) AND status IN (?) GROUP BY user_id",
             [$course_ids, $user_ids, ['user', 'autor']], $sum);
diff --git a/lib/classes/coursewizardsteps/LVGroupsWizardStep.php b/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
index 6d5f20c278d65d997393bbfa8db4db78ed24da32..93f2c1b98b0fa6e167be9bf437186cfbe8cdffcd 100644
--- a/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
+++ b/lib/classes/coursewizardsteps/LVGroupsWizardStep.php
@@ -444,7 +444,7 @@ class LVGroupsWizardStep implements CourseWizardStep
             $area = Lvgruppe::find($lvg_id);
             $selection->add($area);
         }
-        LvGruppe::setLvgruppen($course->id, $selection->getLvgruppenIDs());
+        Lvgruppe::setLvgruppen($course->id, $selection->getLvgruppenIDs());
 
         return $course;
     }
diff --git a/lib/cronjobs/check_admission.class.php b/lib/cronjobs/check_admission.class.php
index 600598b48f4dafc402d6dfe74098fe72633fa010..cac69a5789dce70574a1593e7e254de54a034607 100644
--- a/lib/cronjobs/check_admission.class.php
+++ b/lib/cronjobs/check_admission.class.php
@@ -60,7 +60,7 @@ class CheckAdmissionJob extends CronJob
                   INNER JOIN coursesets USING(set_id)
                   WHERE type = 'ParticipantRestrictedAdmission'
                     AND algorithm_run = 0";
-        $sets = DbManager::get()->fetchFirst($query);
+        $sets = DBManager::get()->fetchFirst($query);
         if (count($sets) > 0) {
             if ($verbose) {
                 echo date('r') . ' - Starting seat distribution ' . chr(10);
diff --git a/lib/elearning/ELearningUtils.class.php b/lib/elearning/ELearningUtils.class.php
index 86dd037f7e1b023fb439e835dd906f126b68ce73..c5b22d1a362c1bf7a5a14fdcb84eb78a95362e0c 100644
--- a/lib/elearning/ELearningUtils.class.php
+++ b/lib/elearning/ELearningUtils.class.php
@@ -483,9 +483,9 @@ class ELearningUtils
                 if (self::isCMSActive($system_type)) {
                     self::loadClass($system_type);
                     $connected_courses['courses'][$system_type] = [
-                        'url' => UrlHelper::getLink($connected_cms[$system_type]->link->cms_link . '?client_id=' . $connected_cms[$system_type]->getClientId() . '&cms_select=' . $system_type . '&ref_id=' . $crs_id . '&type=crs&target=start'),
+                        'url' => URLHelper::getLink($connected_cms[$system_type]->link->cms_link . '?client_id=' . $connected_cms[$system_type]->getClientId() . '&cms_select=' . $system_type . '&ref_id=' . $crs_id . '&type=crs&target=start'),
                         'cms_name' => $connected_cms[$system_type]->getName()];
-                    $course_output[] = "<a href=\"" . UrlHelper::getLink($connected_cms[$system_type]->link->cms_link . "?" . "client_id=" . $connected_cms[$system_type]->getClientId() . "&cms_select=" . $system_type . "&ref_id=" . $crs_id . "&type=crs&target=start") . "\" target=\"_blank\" rel=\"noopener noreferrer\">".sprintf(_("Kurs in %s"), htmlReady($connected_cms[$system_type]->getName()))."</a>";
+                    $course_output[] = "<a href=\"" . URLHelper::getLink($connected_cms[$system_type]->link->cms_link . "?" . "client_id=" . $connected_cms[$system_type]->getClientId() . "&cms_select=" . $system_type . "&ref_id=" . $crs_id . "&type=crs&target=start") . "\" target=\"_blank\" rel=\"noopener noreferrer\">".sprintf(_("Kurs in %s"), htmlReady($connected_cms[$system_type]->getName()))."</a>";
                     // gegebenenfalls zugeordnete Module aktualisieren
                     if (Request::option('update')) {
                         if ((method_exists($connected_cms[$system_type], "updateConnections"))) {
diff --git a/lib/elearning/Ilias4ConnectedLink.class.php b/lib/elearning/Ilias4ConnectedLink.class.php
index ea241e857ec794109bd55f679b98cc8f6f91e337..a66bd8e0a5c0997ad09c270597e92f109939a3b7 100644
--- a/lib/elearning/Ilias4ConnectedLink.class.php
+++ b/lib/elearning/Ilias4ConnectedLink.class.php
@@ -46,7 +46,7 @@ class Ilias4ConnectedLink extends Ilias3ConnectedLink
         if ($connected_cms[$this->cms_type]->isAuthNecessary() AND (! $connected_cms[$this->cms_type]->user->isConnected())) {
             return false;
         }
-        $output = "<a href=\"" . UrlHelper::getLink($this->cms_link . "?"
+        $output = "<a href=\"" . URLHelper::getLink($this->cms_link . "?"
         . "client_id=" . $connected_cms[$this->cms_type]->getClientId()
         . "&cms_select=" . $this->cms_type
         . "&ref_id=" . $module_id
diff --git a/lib/functions.php b/lib/functions.php
index c4ff703ff465ca6aada45242043479f05a00d53b..0c30bfafd6e7c23490ca0b96b1f4648c3f8ac88c 100644
--- a/lib/functions.php
+++ b/lib/functions.php
@@ -1588,7 +1588,7 @@ function strtokebabcase($string) {
  * @return int number of rows
  */
 function count_table_rows($table) {
-    $stat = DbManager::get()->fetchOne("SHOW TABLE STATUS LIKE ?", [$table]);
+    $stat = DBManager::get()->fetchOne("SHOW TABLE STATUS LIKE ?", [$table]);
     return (int)$stat['Rows'];
 }
 
diff --git a/lib/models/AdmissionApplication.class.php b/lib/models/AdmissionApplication.class.php
index 74c79860a3eac66fb488e003a317f21b688a2aaf..21cd1f46e3327f48855f5e14cba2bc32a6f81c5e 100644
--- a/lib/models/AdmissionApplication.class.php
+++ b/lib/models/AdmissionApplication.class.php
@@ -56,7 +56,7 @@ class AdmissionApplication extends SimpleORMap implements PrivacyObject
 
     public static function findByCourse($course_id)
     {
-        $db = DbManager::get();
+        $db = DBManager::get();
         return $db->fetchAll("SELECT admission_seminar_user.*, aum.vorname,aum.nachname,aum.email,
                              aum.username,ui.title_front,ui.title_rear
                              FROM admission_seminar_user
@@ -69,7 +69,7 @@ class AdmissionApplication extends SimpleORMap implements PrivacyObject
 
     public static function findByUser($user_id)
     {
-        $db = DbManager::get();
+        $db = DBManager::get();
         return $db->fetchAll("SELECT admission_seminar_user.*, seminare.Name as course_name
                              FROM admission_seminar_user
                              LEFT JOIN seminare USING (seminar_id)
diff --git a/lib/models/Message.class.php b/lib/models/Message.class.php
index f786f938da4040068e80daaa743c09e433986be6..a384f6459a2dd8867143eb87a1929adf52487691 100644
--- a/lib/models/Message.class.php
+++ b/lib/models/Message.class.php
@@ -156,7 +156,7 @@ class Message extends SimpleORMap implements PrivacyObject
                     ORDER BY Nachname, Vorname";
             $params = [$this->receivers->pluck('user_id')];
         }
-        $db = DbManager::get();
+        $db = DBManager::get();
         return new SimpleCollection(
             $db->fetchAll($sql,
                              $params,
diff --git a/lib/models/MvvCourse.php b/lib/models/MvvCourse.php
index 801a08e99bb1e21ad66d025da07eb99d8f189226..0e82d3bcb0fca94b8cc543299b9bc3d53206ec41 100644
--- a/lib/models/MvvCourse.php
+++ b/lib/models/MvvCourse.php
@@ -37,7 +37,7 @@ class MvvCourse extends ModuleManagementModelTreeItem
      */
     public function getTrailParent()
     {
-        return LvGruppe::findCached($this->getTrailParentId());
+        return Lvgruppe::findCached($this->getTrailParentId());
     }
 
     /**
diff --git a/lib/models/User.class.php b/lib/models/User.class.php
index 8760e0cce14bbbbd62f9892fb0099b0073e888b6..cdc84e462a208e9ab091af0708636f30809ba17a 100644
--- a/lib/models/User.class.php
+++ b/lib/models/User.class.php
@@ -249,7 +249,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject
                 FROM auth_user_md5
                 LEFT JOIN user_info USING (user_id)
                 WHERE user_id = ?";
-        $data = DbManager::get()->fetchOne($sql, [$id]);
+        $data = DBManager::get()->fetchOne($sql, [$id]);
         if ($data) {
             return self::buildExisting($data);
         }
@@ -268,7 +268,7 @@ class User extends AuthUserMd5 implements Range, PrivacyObject
                 FROM auth_user_md5
                 LEFT JOIN user_info USING (user_id)
                 WHERE user_id IN (?) " . $order_by;
-        $data = DbManager::get()->fetchAll($sql, [$ids], 'User::buildExisting');
+        $data = DBManager::get()->fetchAll($sql, [$ids], 'User::buildExisting');
         return $data;
     }
 
@@ -1118,9 +1118,9 @@ class User extends AuthUserMd5 implements Range, PrivacyObject
             $new_avatar = Avatar::getAvatar($new_id);
             if ($old_avatar->is_customized()) {
                 if (!$new_avatar->is_customized()) {
-                    $avatar_file = $old_avatar->getFilename(AVATAR::ORIGINAL);
+                    $avatar_file = $old_avatar->getFilename(Avatar::ORIGINAL);
                     if (!file_exists($avatar_file)) {
-                        $avatar_file = $old_avatar->getFilename(AVATAR::NORMAL);
+                        $avatar_file = $old_avatar->getFilename(Avatar::NORMAL);
                     }
                     $new_avatar->createFrom($avatar_file);
                 }
diff --git a/lib/models/UserStudyCourse.class.php b/lib/models/UserStudyCourse.class.php
index ac7670c198f1d6d5cf2b9c07493cde701e9b043d..7f7ad3489f7be97ebb073fd965b17fe8e3eb1098 100644
--- a/lib/models/UserStudyCourse.class.php
+++ b/lib/models/UserStudyCourse.class.php
@@ -50,7 +50,7 @@ class UserStudyCourse extends SimpleORMap implements PrivacyObject
 
     public static function findByUser($user_id)
     {
-        $db = DbManager::get();
+        $db = DBManager::get();
         $st = $db->prepare("SELECT user_studiengang.*, abschluss.name as degree_name,
                             fach.name as studycourse_name
                             FROM user_studiengang
diff --git a/public/show_bereich.php b/public/show_bereich.php
index 62595eeec1d73366cc476593bf8f684e965ea9f0..48d3cf14406f5a11da655788022996faabe0ffbf 100644
--- a/public/show_bereich.php
+++ b/public/show_bereich.php
@@ -77,7 +77,7 @@ case "sbb":
     $excel_text = strip_tags(DecodeHtml($intro_text));
     break;
 case "s":
-    $db = DbManager::get();
+    $db = DBManager::get();
     $bereich_typ=_("Einrichtung");
     $head_text = _("Ãœbersicht aller Veranstaltungen einer Einrichtung");
     $intro_text = sprintf(_("Alle Veranstaltungen der Einrichtung: <b>%s</b>"), htmlReady(Institute::find($id)->name));
diff --git a/tests/jsonapi/ConsultationsBookingCreateBySlotIndexTest.php b/tests/jsonapi/ConsultationsBookingCreateBySlotIndexTest.php
index 058e5dd570c3514425bb5692d1a421f43fc4e48b..2d9be45ee5015f5a3dc30b222ccd450199e9893e 100644
--- a/tests/jsonapi/ConsultationsBookingCreateBySlotIndexTest.php
+++ b/tests/jsonapi/ConsultationsBookingCreateBySlotIndexTest.php
@@ -1,7 +1,7 @@
 <?php
 use JsonApi\Routes\Consultations\BookingsCreate;
 use JsonApi\Schemas\ConsultationBooking as Schema;
-use JsonAPi\Schemas\User as UserSchema;
+use JsonApi\Schemas\User as UserSchema;
 use WoohooLabs\Yang\JsonApi\Response\JsonApiResponse;
 
 require_once __DIR__ . '/ConsultationHelper.php';
diff --git a/tests/jsonapi/ConsultationsBookingCreateTest.php b/tests/jsonapi/ConsultationsBookingCreateTest.php
index 493bf97efa83f8baf7dd3aa7844f6a3a871f8e81..e8a85c9aa61849f588e4a58fca6c9006e5f820e8 100644
--- a/tests/jsonapi/ConsultationsBookingCreateTest.php
+++ b/tests/jsonapi/ConsultationsBookingCreateTest.php
@@ -1,8 +1,8 @@
 <?php
 use JsonApi\Routes\Consultations\BookingsCreate;
 use JsonApi\Schemas\ConsultationBooking as Schema;
-use JsonAPi\Schemas\User as UserSchema;
-use JsonAPi\Schemas\ConsultationSlot as SlotSchema;
+use JsonApi\Schemas\User as UserSchema;
+use JsonApi\Schemas\ConsultationSlot as SlotSchema;
 use WoohooLabs\Yang\JsonApi\Response\JsonApiResponse;
 
 require_once __DIR__ . '/ConsultationHelper.php';