Adobe Reader DC File Cannot be Found Error

I have been having this error on only two files in a certain folder, on a certain drive. All other PDF's on the drive are fine and able to be opened through Reader DC. But when one of the working ones is copied into this folder it fails to work. And vice versa, if one is copied out of the folder, it still is unable to be opened.

The protected mode disable is the only way I have been able to solve this. BUT - I want to know if disabling this actually increases security risks as there is a lot of data on the drive.

Also, if security risks are too great when disabling the protected mode, what solutions are available? I have already ran a repair on the app itself. Removed and reinstalled the app and finally made the app the default when opening PDF's. These were all the solutions I could find across the internet, amongst various forums and articles. ]

Any help is greatly appreciated