@rjbran can you clarify something, please? After deleting the form, did you then go back and revisit the foreign tax credit section so the form would be regenerated? Or did you submit immediately. If you submitted immediately I'd expect that you'd end up either not claiming the foreign tax credit (which would affect the total tax owed) or claiming it without the form (which I'd expect to cause problems). But I'm not an expert, so who knows.
I did try deleting the whole form then revisiting the interview sections to regenerate it, and that didn't let me submit. I didn't try submitting without regenerating the form. Let us know what response you get, and whether yours is an original or amended return.
