This issue kind of walks the line b/w repeatable and sporadic.  It doesn't happen if I open WO-A and enter just one WO but if I enter multiple WO's it will happen eventually every time.
 
Once I press Save I get the following:
 
WARN ERR - File T7WOA.SRC line: 563
An error message record was not found in the ERRMSG.B file. 404
 
After I press OK on the error pop up the program (WO-A) quits and the WO is not saved.
 
Actually, sometimes it does save but most of the time it does not.  I just now got this error msg and the WO did save but I see that the Finish Date shows 01/01/00