I suddenly have a user unable to open pdfs saved from a specific website. I have been running down the rabbit hole trying to solve this issue.
The user is opening the file through the File->Open in Adobe Acrobat, the file is saved locally and not opened in a browser but they still get this message:
The one thing I have done that seemed to work at least temporarily was reset her profile. Which basically blanked out her appdata. I tried replacing just her adobe appdata but that didnt work so its something else entirely.