Sometimes what you select from the pdf drop down menu will cause problems along with the description you type in. Try deleting the existing pdf and then try adding the pdf again. In a worst case scenario you can always paper file.
Yes, had to use a specific item of the drop down list to clear error. "other" type would not work. So I tried everyone of items until error cleared. So don't want to file paper returns these.
When you type in description do not use word "form" just use number or schedule IE. 1040 schedule D. I have never had any PDF fail to attach using other, and not putting the word form in description
