We are experiencing the same problem as a company. Although we called for Apple Support for 2 days, they could not find a solution. They just say they will escalate to the Developer team...

i solved, Specified something in the copyright field and it worked.

Found the error! I could submit now! The copyright field is now required! This must be new! Didn't have this problem two weeks ago. Wished the error message would have been clearer!