Symptom
After an upgrade of SAP NetWeaver BPM to EhP2 this message might appear in the problems view in NWDS for existing proceses. As EhP1 only knew asynchronous process calls there wasn't any check for this. Starting with EhP2 start and end events need to be based on the same operation.
The following constraint violation is shown for an existing process after upgrade to EHP2: "Constraint violation: End event "End" must have the same operation as the synchronous start event"
HINTS
For this issue to occur the process must have different operations assigned to the start and end event. Having different operations on start and end event does not make sense but do not cause any problems in EHP1 since there were no synchronous process calls. In EHP2 having the same operation in both places is necessary.
Solution
Assign the same operation to the end event that is assigned to the start event.