Add Ron's suggestions.

app/controllers/admin/courseware.php

@@ -53,7 +53,8 @@ class Admin_CoursewareController extends AuthenticatedController
                 return $this->deactivate_block_types_action();
         }
 
-        throw new Trails_Exception(400);
+        PageLayout::postInfo(_("Keine Aktion ausgewählt."));
+        $this->redirect($this->action_url('block_types'));
     }
 
     /**
@@ -138,7 +139,8 @@ class Admin_CoursewareController extends AuthenticatedController
                 return $this->deactivate_container_types_action();
         }
 
-        throw new Trails_Exception(400);
+        PageLayout::postInfo(_("Keine Aktion ausgewählt."));
+        $this->redirect($this->action_url('container_types'));
     }
 
     /**

app/views/admin/courseware/block_types.php

 <form method="post" action="<?= URLHelper::getLink('dispatch.php/admin/courseware/block_types') ?>">
     <?= CSRFProtection::tokenTag() ?>
-    <div>
-        <select name="bulk_action">
-            <option disabled selected hidden><?= _('Mehrfachaktionen') ?></option>
-            <option value="activate"><?= _('Aktivieren') ?></option>
-            <option value="deactivate"><?= _('Deaktivieren') ?></option>
-        </select>
-        <button type="submit" formaction="<?= URLHelper::getLink('dispatch.php/admin/courseware/bulk_block_types') ?>" class="button"><?= _('Übernehmen') ?></button>
-    </div>
     <table class="default sortable-table cw-admin-block-types">
+        <tfoot>
+            <tr>
+                <td colspan="5">
+                    <select name="bulk_action">
+                        <option disabled selected hidden><?= _('Mehrfachaktionen') ?></option>
+                        <option value="activate"><?= _('Aktivieren') ?></option>
+                        <option value="deactivate"><?= _('Deaktivieren') ?></option>
+                    </select>
+                    <button type="submit" formaction="<?= URLHelper::getLink('dispatch.php/admin/courseware/bulk_block_types') ?>" class="button"><?= _('Übernehmen') ?></button>
+                </td>
+            </tr>
+        </tfoot>
         <thead>
             <tr>
                 <th>

app/views/admin/courseware/container_types.php

 <form method="post" action="<?= URLHelper::getLink('dispatch.php/admin/courseware/container_types') ?>">
     <?= CSRFProtection::tokenTag() ?>
-    <div>
-        <select name="bulk_action">
-            <option disabled selected hidden><?= _('Mehrfachaktionen') ?></option>
-            <option value="activate"><?= _('Aktivieren') ?></option>
-            <option value="deactivate"><?= _('Deaktivieren') ?></option>
-        </select>
-        <button type="submit" formaction="<?= URLHelper::getLink('dispatch.php/admin/courseware/bulk_container_types') ?>" class="button"><?= _('Übernehmen') ?></button>
-    </div>
     <table class="default sortable-table cw-admin-container-types">
+        <tfoot>
+            <tr>
+                <td colspan="5">
+                    <select name="bulk_action">
+                        <option disabled selected hidden><?= _('Mehrfachaktionen') ?></option>
+                        <option value="activate"><?= _('Aktivieren') ?></option>
+                        <option value="deactivate"><?= _('Deaktivieren') ?></option>
+                    </select>
+                    <button type="submit" formaction="<?= URLHelper::getLink('dispatch.php/admin/courseware/bulk_container_types') ?>" class="button"><?= _('Übernehmen') ?></button>
+                </td>
+            </tr>
+        </tfoot>
         <thead>
             <tr>
                 <th>

db/migrations/5.6.1_create_block_type_states.php

@@ -13,7 +13,7 @@ class CreateBlockTypeStates extends Migration
         $query =
             "CREATE TABLE IF NOT EXISTS `cw_block_type_states` (
              `id` int(11) NOT NULL AUTO_INCREMENT,
-             `block_type` VARCHAR(300) NOT NULL,
+             `block_type` VARCHAR(255) NOT NULL,
              `activated` TINYINT(1) NOT NULL DEFAULT 0,
              `mkdate` int(11) UNSIGNED NOT NULL,
              `chdate` int(11) UNSIGNED NOT NULL,

db/migrations/5.6.2_create_container_type_states.php

@@ -13,7 +13,7 @@ class CreateContainerTypeStates extends Migration
         $query =
             "CREATE TABLE IF NOT EXISTS `cw_container_type_states` (
              `id` int(11) NOT NULL AUTO_INCREMENT,
-             `container_type` VARCHAR(300) NOT NULL,
+             `container_type` VARCHAR(255) NOT NULL,
              `activated` TINYINT(1) NOT NULL DEFAULT 0,
              `mkdate` int(11) UNSIGNED NOT NULL,
              `chdate` int(11) UNSIGNED NOT NULL,