I have reviewed this template and I see no reason you should be getting this message. Say yes to allow duplicate value and then do View > Find and type an exclamation in the Product Number field and see if you get any results. ! looks for duplicate entries. Do you get any results?
Have you changed anything on the field definition for Part Number? I am at a loss on why it is set up on auto-enter data blank. It certainly doesn't stop imports (with auto-enter selected) from blanking the part number; in fact, I see no purpose in it at all. But that, I believe, is beside the point - you still shouldn't be getting this message. I cannot replicate the issue. Has this file crashed?
One more thing to try: Turn off validation unique for a moment (this must be done if we want to force indexing to refresh). Then go to the storage tab in options. Change indexing to 'None' and then exit field definitions back to your layout. Then go back in and change validation back to unique. You will not need to re-set the indexing since validation unique requires it - it will come back on automatically.
thanks so much for your answer and suggestions.
I entered '!' in the find field and got no duplicates.
I don't think I made any changes to the field definition for Part Number.
I made the changes you suggested and then re-entered settings. Didn't appear to make any difference.
Is there anything else I can give you that might help?