                 nextProperty!.previousPropertyID = previousPropertyID
                 
                 // CONTEXT WRITE
-                context.update(nextProperty!)
+                context.update(&nextProperty!)
             } else {
                 // ERROR: nextPropertyID is not zero but readProperty return nil
                 assertionFailure("ERROR: Database inconsistent")

                previousProperty!.nextPropertyID = nextPropertyID
                
                // CONTEXT WRITE
                context.update(previousProperty!)
            } else {
                // ERROR: previousProperty is not zero but readProperty return nil
                assertionFailure("ERROR: Database inconsistent")

                // CONTEXT WRITE
                // updated of the LAST relationship is only required if
                // the is was extended
                context.update(&lastProperty!)
            } else {
                // ERROR: lastProperty is nil even nextPropertyID is not set to zero
                assertionFailure("ERROR: Database inconsistent")
