An error may occur when switching from multi-currency to non-multi-currency in GP. Follow Dynamics GP recommended practices when changing from non-multi-currency to multi-currency.

Tasks should be Check-Links; if that does not remove the currency attached to a check book, errors will occur when you try to save kit items. If you remove the currency code on all check books, you should be able to save. The check book table in GP is CM00100.