Hello John,
You can check that register (work item number) directly in transaction SWIA.
Now, you must have a job with status error in SM37 when searching for job name *WI*.
Within this job details, you must have an error. You can also check in ST22 for the dump this job has generated (ASSERTION_FAILED in class CL_GRFN_OWP_DELIVER).
Regards,
Ferrnando