E-filed last year but says form preventing e-file this year. Does not tell me what form.

I am having the same problem when i add my schedule C

I switched to the "forms" view. I found forms that seemed to be residual from past years. I started deleting suspect forms that seemed irrelevant. I would run the check after each until the review went through and I could once again e-file. I still do not know what form did the trick, but it worked. Hope this helps someone