[JAVA API] Connector.Update() throws Exception

[real-time-systems]

Hello,
if try to update a connector (org.sparx.Connector) i get the following Java exception from the API.

Exception in thread "main" java.lang.Exception: I
at org.sparx.Connector.comUpdate(Native Method)
at org.sparx.Connector.Update(Connector.java:538 )

The following sample code prints some properties of a connector and tries to update the connector.

eaConnector = rep.GetConnectorByID(1952);
System.out.println("id=" + eaConnector.GetConnectorID());
System.out.println("type=" + eaConnector.GetType());
System.out.println("subtype=" + eaConnector.GetSubtype());
System.out.println("dir=" + eaConnector.GetDirection());
System.out.println("stereotype=" + eaConnector.GetStereotype());
eaConnector.Update();

If the connector is an Association or a Generalization no exception is thrown.
But if this connector is an include or extend within a UseCase diagramm the exception is thrown!

The exception is thrown with EA 7.0 Buld 813 and Build 818.

Can anybody help me?
Is there a java API (and SSJavaCOM.dll) that works?