The split will not be the problem; in fact, it's the recommended way (one FE copy per user). That error is usually due to some reference that cannot be resolved. Closing/reopening the db often clears the ambiguity by resetting something back to the design point, so the solution is likely to get that setting to be re-applied, assuming it is appropriate for the task. However, doing data entry on tabs doesn't sound right. The task isn't clear so I'm only guessing when I say that one main form or a main form with a subform is likely more appropriate. If you're going to stick with the current process, more info is needed, or you could compact/repair your db and post a zipped copy of it here. I may not be able to open it.
Last edited by Micron; 02-16-2017 at 08:47 AM.
Reason: clarification
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.