The only way I can see to make this work, is apply the credit for 2014, to 2015. File an amended return for 2015. The enter the resulting excess payment (and too small refund) for 2015 as a credit for 2016, in line 65 of 1040, for my 2016 return.
Similarly, I will have to start a new *.tax15 file, from the changed *.tax14 file. Then use the amended *.tax15 file, as the starting point for my *.tax16 file.
Is there an easier way?
