Error 3631:Violation of PRIMARY KEY constraint 'PL_tblitemLot'. Cannot insert Duplicate Key.

This error typically occurs when a SD has the same item listed on Multiple lines and one line is deleted.
The workaround is to save the SD as soon as you delete the line, and then continue working. You can also try changing the line to be a different item before deleting it.

If you continue to have this error after the above steps, please contact NumberCruncher Support.