diff --git a/Services/WebServices/ECS/classes/Course/class.ilECSCmsCourseMemberCommandQueueHandler.php b/Services/WebServices/ECS/classes/Course/class.ilECSCmsCourseMemberCommandQueueHandler.php
index 284bd2e8fb57..94c75c81f0b2 100644
--- a/Services/WebServices/ECS/classes/Course/class.ilECSCmsCourseMemberCommandQueueHandler.php
+++ b/Services/WebServices/ECS/classes/Course/class.ilECSCmsCourseMemberCommandQueueHandler.php
@@ -225,12 +225,12 @@ protected function readAssignments($course, $course_member): array
                 // the sequence number in the course ressource
                 $sequence_number = (int) $pgroup->num;
                 // find parallel group with by sequence number
-                $tmp_pgroup = $course->groups[$sequence_number];
+                $tmp_pgroup = $course->groups[$sequence_number] ?? null;
                 if (is_object($tmp_pgroup) && $tmp_pgroup->id !== '') {
                     $this->log->debug('Found parallel group with id: ' . $tmp_pgroup->id . ': for sequence number: ' . $sequence_number);
 
                     // @todo check hierarchy of roles
-                    $assigned[$tmp_pgroup->id][$member->personID] = array(
+                  $assigned[$pgroup->id][$member->personID] = array(
                         'id' => $member->personID,
                         'role' => $pgroup->role
                     );
@@ -459,7 +459,7 @@ private function readCourseMember(ilECSSetting $server, $a_content_id)
      */
     private function readCourse($course_member)
     {
-        $ecs_id = ilECSImportManager::getInstance()->lookupEContentIdByContentId(
+        $ecs_id = ilECSImportManager::getInstance()->lookupLatestEContentIdByContentId(
             $this->getServer()->getServerId(),
             $this->getMid(),
             $course_member->lectureID
diff --git a/Services/WebServices/ECS/classes/class.ilECSImportManager.php b/Services/WebServices/ECS/classes/class.ilECSImportManager.php
index 95757d05aa05..1dacf3e86cb8 100644
--- a/Services/WebServices/ECS/classes/class.ilECSImportManager.php
+++ b/Services/WebServices/ECS/classes/class.ilECSImportManager.php
@@ -121,6 +121,20 @@ public function lookupEContentIdByContentId($a_server_id, $a_mid, $a_content_id)
         return 0;
     }
 
+    public function lookupLatestEContentIdByContentId($a_server_id, $a_mid, $a_content_id): int
+    {
+        $query = 'SELECT * from ecs_import ' .
+            'WHERE server_id = ' . $this->db->quote($a_server_id, 'integer') . ' ' .
+            'AND mid = ' . $this->db->quote($a_mid, 'integer') . ' ' .
+            'AND content_id = ' . $this->db->quote($a_content_id, 'text') . ' ' .
+            'ORDER BY econtent_id DESC';
+        $res = $this->db->query($query);
+        if ($row = $res->fetchRow(ilDBConstants::FETCHMODE_OBJECT)) {
+            return (int) $row->econtent_id;
+        }
+        return 0;
+    }
+
     /**
      * get all imported links
      *