Fill and sign error the operation failed because adobe acrobat dc encounter an unknown error

Greetings,

I am having issue with "some" of our PDFs where if I go to do fill & sign & attempt to add a signature it returns with the following error after I attempt to save the changes. 

I thought it was because I was opening & saving to a network drive via VPN but when I save the same file locally the issue persisted. 

So I created the PDF using "Print to PDF" from Adobe Acrobat 2015. Save that newly created PDF & the issue was resolved. 

This is a cumbersome process especially with multiple PDFs. Does anyone have a root cause? The PDFs come from different sources so I can't validate how the PDF was created or what application but is this a known issue?

Also I did try to perform updates from the help drop down but there were no updates available. 

Windows 10 Pro x64 Edition 10.0 (build: 17134)

Adobe 2015 (ver 15.006.30527)