The following intermittent errors can display when you save an FRP encrypted file:
Microsoft WordPad examples:
Access to c:\Users\admin\Documents\document.rtf was denied
The document c:\Users\admin\Documents\document.rtf is in use by another application and cannot be accessed
Microsoft Paint examples:
A sharing violation occurred while accessing c:\Users\admin\Pictures\test.png
Access to c:\users\admin\Pictures\test.png was denied
You see this intermittent issue on systems that have an enforced FRP 5.x Application-based Protection policy. The policy sets all files to be encrypted with a key for a given process.
Process examples: