diff --git a/src/goose/goose_publisher.c b/src/goose/goose_publisher.c
index 51e455a0..97b536fa 100644
--- a/src/goose/goose_publisher.c
+++ b/src/goose/goose_publisher.c
@@ -318,7 +318,14 @@ createGoosePayload(GoosePublisher self, LinkedList dataSetValues, uint8_t* buffe
     while (element != NULL) {
         MmsValue* dataSetEntry = (MmsValue*) element->data;
 
-        dataSetSize += MmsValue_encodeMmsData(dataSetEntry, NULL, 0, false);
+        if (dataSetEntry) {
+            dataSetSize += MmsValue_encodeMmsData(dataSetEntry, NULL, 0, false);
+        }
+        else {
+            /* TODO encode MMS NULL */
+            if (DEBUG_GOOSE_PUBLISHER)
+                printf("GOOSE_PUBLISHER: NULL value in data set!\n");
+        }
 
         element = LinkedList_getNext(element);
     }
@@ -384,7 +391,12 @@ createGoosePayload(GoosePublisher self, LinkedList dataSetValues, uint8_t* buffe
     while (element != NULL) {
         MmsValue* dataSetEntry = (MmsValue*) element->data;
 
-        bufPos = MmsValue_encodeMmsData(dataSetEntry, buffer, bufPos, true);
+        if (dataSetEntry) {
+            bufPos = MmsValue_encodeMmsData(dataSetEntry, buffer, bufPos, true);
+        }
+        else {
+            /* TODO encode MMS NULL */
+        }
 
         element = LinkedList_getNext(element);
     }
diff --git a/src/iec61850/server/mms_mapping/control.c b/src/iec61850/server/mms_mapping/control.c
index 5bed8f1e..5f036e66 100644
--- a/src/iec61850/server/mms_mapping/control.c
+++ b/src/iec61850/server/mms_mapping/control.c
@@ -1828,8 +1828,13 @@ Control_readAccessControlObject(MmsMapping* self, MmsDomain* domain, char* varia
                         ControlObject_getTypeSpec(controlObject), varName);
             }
         }
-        else
+        else {
             value = ControlObject_getMmsValue(controlObject);
+        }
+    }
+    else {
+        if (DEBUG_IED_SERVER)
+            printf("IED_SERVER: Control object not found %s/%s.%s\n", domain->domainName, lnName, objectName);
     }
 
     return value;
diff --git a/src/iec61850/server/mms_mapping/mms_mapping.c b/src/iec61850/server/mms_mapping/mms_mapping.c
index 47348dd3..8fa84487 100644
--- a/src/iec61850/server/mms_mapping/mms_mapping.c
+++ b/src/iec61850/server/mms_mapping/mms_mapping.c
@@ -3684,15 +3684,15 @@ MmsMapping_triggerGooseObservers(MmsMapping* self, MmsValue* value)
 void
 MmsMapping_enableGoosePublishing(MmsMapping* self)
 {
+    LinkedList element = LinkedList_getNext(self->gseControls);
 
-    LinkedList element = self->gseControls;
-
-    while ((element = LinkedList_getNext(element)) != NULL) {
-        MmsGooseControlBlock gcb = (MmsGooseControlBlock) element->data;
+    while (element) {
+        MmsGooseControlBlock gcb = (MmsGooseControlBlock) LinkedList_getData(element);
 
         MmsGooseControlBlock_enable(gcb, self);
-    }
 
+        element = LinkedList_getNext(element);
+    }
 }
 
 void