I use ProSeries, and you have to follow instructions very carefully for it to work. If you can't get rid of errors just mail it in. It takes only a few days less for the IRS to process an efiled vs mail in for an amended return. Here is a link to the instructions.

https://accountants.intuit.com/support/en-us/help-article/form-1040/amending-individual-1040x-return...