Fill & Sign - 'The operation failed because Adobe Acrobat encountered an unknown error.'

Issue started today with a specific file.  Attempted to remove all protection but still did not allow the inserting of text or a signature.  Had to print to new PDF version and save it.  I was then able to add the signature.  I do not understand what would be causing this.  Any chance getting comments from somone within Adobe to chime in?

I have mutliple users in my organization get this error message while trying to fill and sign a PDF in Adobe Reader that I added form fields to. Why are they getting these errors?

Yes all an uncredentialled idiot wanted to do was take over my computer 

Found this to be the most helpful resource for getting access to signatures on pdfs again.

https://www.foxit.com/pdf-reader/

For window 10 users, use Mircosoft to PDF, to recreate the PDF vs adobe and that should work.

I ran into this same problem working from home and trying to add signatures to drawings.  The workaround I found that was successful was by clicking on the "Protect" tool in Adobe Acrobat Pro DC and then "Remove Hidden Information".  Click on the "Remove" button that shows up on the left side of the screen and you can watch as it removes "Metadata, Bookmarks, Comments and markups and Overlapping objects".  Once this hidden info is removed click on "Close". 

At this point I was able to click on the "Fill & Sign" button and add my signature.  Not the best approach but it allowed me to keep working.

I realize this thread is a couple of years old, but I also noticed that only 1 time did an Adobe employee come in to help. And it was crappy help at that. Better instructions and considerations to carry out those instructions would have been helpful. Thanks for nothing Adobe...it's 3 years later, and you still haven't got it right yet! 

Same error message for me!

I've tried different files and it's the same error. I can neither fill nor sign.

The cloud option worked, https://cloud.acrobat.com/fillsign

I’ve encountered this problem for the first time today. I have a Mac desktop version (not cloud), and the workarounds don’t work. I have no option of contacting “Customer Care,” so I’m screwed.

Hey Adobe.... Nothing? Clearly the workaround only works for some people!

It's definitely something in the file, cause I can add images/sign other pdf documents. But exporting or 'printing' from an excel file creates a pdf that won't allow me to sign. Sadly, I really REALLY have to find a solution because it is the expected delivery (printing it out, signing, scanning and then sending is not only tedious but also would require a printer/scanner - which I have no access to).

Please help!