Check the server log for the name of the of the task or process that this happens. Then in the soa dehydration store, check the status of this process via the query. select processId, processName, compositeName, revision, status from dev_soainfra.BPM_CUBE_PROCESS;
for the process set the status='-1'.
Restart the soa server and try again.
Hope this helps..cheers!