This was super helpful! Worked great for me. I had this error come up when trying to file my 1065 partnership return. The issue was that I had uploaded a PDF of my form 8453-PE (Georgia requires this), which I had created and had a large file size. I re-uploaded the form as a jpeg instead, and let TurboTax format it into a PDF (which they helpfully do). I was able to file my taxes after that. Thanks for posting this!
