PDFs wont save Highlights and Comments

[Kyle5FE0]

I can't save a specific PDF after highlighting and marking up.

When I try to save the saving bar gets about half-way and freezes. I try to save-as and Acrobat freezes and won't let me save. I have tried re-installing and repairing. I created a new copy of the file and renamed it and the same issue keeps happening. 

I am a law student who uses the program to mark-up textbooks and case law, it is necessary that I c.

Any suggestions?

[ls_rbls]

Maybe that particular file has password protection and enforcing some restrictions.

Have you checked if this file is password protected? Or which was the source software used to produce this PDF?

[Kyle5FE0]

The weird thing is that 

1) this is not password protected; and

2) This is a textbook I have been marking up for 3 months and had no issue with saving prior to 2 days ago.

I am not sure what the source software is, but given that the problem has only recently arisen, I assume it is a software issue.

[try67]

What's the exact version number of the application (You can find it out by going to Help - About Adobe Acrobat)? What's your OS version?

[Kyle5FE0]

The latest version as far as I am aware - 21.001.20145