After trying everything in this thread with my desktop cx this is what worked for me too.
THIS IS WHAT WORKED:
This finally worked!! go to the section "Other Tax Credits" then "Non-Refundable Credits". After you get to that section, make sure those boxes are blank! I had zeros in both boxes.
It would not continue or save so we logged out and back in and then went back, deleted the zeros, and continued to review and the error was gone.
