If an alert box with the message "error -43" appears, the Users & Groups Data File may have become unusable.
Symptom
When a user attempts to log in, the AppleShare IP File Server quits and an alert box with the message "error -43" appears.
Solution
Use the ASIP First Aid Tool to repair the Users & Groups Data File. If ASIP First Aid reports no faults and the issue persists, reconstruct the Users & Groups Data File anyway. If the issue still persists, export the Users and Groups, delete the Users & Groups Data File, then use the AppleShare IP Setup Assistant to recreate the file.