Earlier this week an expert helped me with a checkbox issue. But I have turned the Main Form into a form with 7 sub-forms. I cannot figure out why when I enter, for example, a Start Time and End Time in the Sunday subform, I get "Invalid use of null" and the times go blank. And yet if I close and re-open the form it seems to look ok. Can someone tell me what is wrong?
Sample file attached.Test.accdb