If you’re working with UserCodes (also called UDCodes) and you’re getting the “input string was not in a correct format” when you explicitly specify the Code ID field, make sure your UD Code Type is not set to autonumber. Autonumbering is a great feature as far as it goes, but if you change your mind and start putting alphanumeric code IDs in the database, the next time you try to create a UDCodes record, Epicor attempts to auto-number and throws the error when it assumes purely numeric Code IDs are in use.
HTH
Monty.