Why getting this error when attaching PDF to Form1041 for e-file? "First extension does not contain PDF file attachments and first extension has already been transmitted"

[PRK]

This makes no sense. I'm trying to attach a PDF with required details to the final return for e-filing. Of course the extension would not contain an attachments, and that should be irrelevant anyway.  I understand the usual process for attaching a PDF.  How do I work around this error and get to the screen where I can attach a PDF?

[ljr · Accepted solution]

try unchecking the extension boxes and just check the efile boxes 

[PRK]

Thank you for that simple but genius suggestion. It worked. Wish I would have thought of that. I appreciate your time.

[1es]

I am having this similar problem, the error shows up as soon as I check the e-file box.

The Extension box is unchecked.