fixes #2374

Closes #2374

Merge request studip/studip!1560

lib/models/resources/ResourceRequest.class.php

@@ -816,16 +816,18 @@ class ResourceRequest extends SimpleORMap implements PrivacyObject, Studip\Calen
             return $start_date;
         }
 
-        $fist_date = $this->cycle->dates->first();
+        if (isset($this->cycle) && count($this->cycle->dates) > 0) {
+            $first_date = $this->cycle->dates->first();
             if ($this->metadate_id && isset($first_date->date)) {
                 $start_date->setTimestamp($first_date->date);
                 return $start_date;
             }
 
             if ($this->course_id && isset($first_date->date)) {
-            $start_date->setTimestamp($fist_date->date);
+                $start_date->setTimestamp($first_date->date);
                 return $start_date;
             }
+        }
 
         if ($this->begin) {
             $start_date->setTimestamp($this->begin);