This is one of TTs worst features. The work around is to just report everything as if it were a single country. Pick the highest tax withholding tax country ( usually Canada, Switzerland or Germany) and gross it all up. Yes, you can do it by the book book, but be prepared for hours of agony. And even if you get it to work, there are still a limited number of countries that you can link to the 1116. Also, as of last year you could not check what you entered and going back resulted in starting all over again.
