I entered a Visit today and entered the Co-Pay (which goes to the Expense Register). When I went to the Expense Register for the expense, I wanted to add the check number to the Memo field, but when I tried to save it, I got a window "Validation failure saving page contents" which contained: 'That change cannot be made: the 'date' field cannot be empty.' The date was not empty because it was already entered from the associated Visit, but somehow it got cleared out, and it wouldn't let me enter the date in the expense register again? So I had to Cancel.