My problem was fixed - box 23 on the T4A(p) had 8 months, and when I keyed in the 8 it was not working, however the problem was that on the same form there were disability income as well and CRA did not have any months in box 21, however the software gave an error unless we put some months into box 21 as well.
I got help from customer service and was able to file.
