We have the problem that we cannot edit PDF files on our DFS share once they are at least in the 5th subfolder. In the folders above it works. It also works with other PDF editors. So the problem is not with the share permissions but with Acrobat Reader. Does anyone have an idea where the problem could be?
Please try to turn off the protected mode for testing and see if that works. Go to Preferences (Ctrl,Cmd+K) > Enhanced Security > Uncheck 'Enable Protected mode at startup' > click ok and reboot the application and check.
Note: Please turn on the security after testing to avoid any security risk.