Index: sources/canbus/messageacknowmodel.cpp
===================================================================
diff -u -r93d7ff58cd6fd2fea5d00587ee712a637fc941bf -r634824d6fce314971aa236e508024bd154562c9d
--- sources/canbus/messageacknowmodel.cpp	(.../messageacknowmodel.cpp)	(revision 93d7ff58cd6fd2fea5d00587ee712a637fc941bf)
+++ sources/canbus/messageacknowmodel.cpp	(.../messageacknowmodel.cpp)	(revision 634824d6fce314971aa236e508024bd154562c9d)
@@ -161,8 +161,10 @@
  */
 void MessageAcknowModel::onAcknowReceive(Sequence vSequence)
 {
-    _acknowList[vSequence]->deleteLater();
-    _acknowList.remove(vSequence);
+    if (_acknowList.contains(vSequence)) {
+        _acknowList[vSequence]->deleteLater();
+        _acknowList.remove(vSequence);
+    }
 }
 
 /*!