After a ton of searching and a form for form - line for line comparison with last year's TT forms, I spotted an anomaly which led to a finding that when I had erroneously answered a question regarding taking required disbursements, then hit "Back" and corrected the answer, then moved on, the problem was created.
A form was created (I failed to save the number but it had an alphabetic suffix) and after correction a value of "0" was left behind. (Which was factually correct.) However, during your fed. error check it was flagged as an error (?) which would not clear even though I tried to add supporting info., tried overriding, tried ignoring ... NOTHING would do away with the error. Then after discovering the "not needed" form, I deleted it and the problem went away. PROBLEM SOLVED.
But, there is a TT program error in that when I did a "legal" BACK and correction, it should NOT have flagged the only remaining "0" entry as an error OR should have removed the no-longer needed form (preferred).