diff --git a/tine20/Felamimail/Controller/AttachmentCache.php b/tine20/Felamimail/Controller/AttachmentCache.php
index 426fafb643f..980c768ea8c 100644
--- a/tine20/Felamimail/Controller/AttachmentCache.php
+++ b/tine20/Felamimail/Controller/AttachmentCache.php
@@ -273,7 +273,11 @@ public function fillAttachmentCache(array $accountIds, ?int $seconds = null): vo
             }
         } finally {
             Tinebase_FileSystem::getInstance()->_getTreeNodeBackend()->doSynchronousPreviewCreation($old);
-            Tinebase_Core::releaseMultiServerLock($lockKey);
+            try {
+                Tinebase_Core::releaseMultiServerLock($lockKey);
+            } catch (Tinebase_Exception_Backend $teb) {
+                Tinebase_Core::getLogger()->notice(__METHOD__ . '::' . __LINE__ . ' ' . $teb->getMessage());
+            }
         }
     }
 }