From 54a7e008913cb30688f779eb9f68c74c2b20d3ca Mon Sep 17 00:00:00 2001
From: Carsten Schmitz <carsten.schmitz@limesurvey.org>
Date: Mon, 8 Nov 2021 16:55:14 +0100
Subject: [PATCH] Fixed issue: Database error when deleting a participant from
 CPDB and connected survey participant tables

---
 application/models/Participant.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/application/models/Participant.php b/application/models/Participant.php
index 10a424127c8..f0aff4f2222 100755
--- a/application/models/Participant.php
+++ b/application/models/Participant.php
@@ -1083,7 +1083,9 @@ public function deleteParticipantTokenAnswer($sParticipantsIDs)
                         if (!empty($tokenAndId['participant_id']) && $surveyTableExists) {
                             /** @var Token $token */
                             $token = Token::model($aSurveyID)->find('participant_id = :pid', [':pid' => $tokenAndId['participant_id']]);
-                            $token->delete();
+                            if (!is_null($token)) {
+                                $token->delete();
+                            }
                         }
                         $iDeletedParticipants = $this->deleteParticipants($sParticipantsIDs, false);
                     }