Is there a way to write protect the music files in MP3Tag

Support
5

That indicates that the file has a simple read-only flag in the file system.
Just use the windows-explorer to enable it again:

  • Mark the files you want to make read-only
  • Make a right-mouse-click and select "Properties"
  • Enable "read-only"

Mp3tag can help you to select this file in the explorer:
File -> Open in explorer

Mp3Tag can also change the read-only attribute with external help.
It is possible to define tools in Mp3tag to call external programs:
File -> Options -> Tools
Click the "New-Button" and define a tool this way
image

You then can mark files in Mp3Tag, make a right-mouse-click, go to tools and select your defined tool for execution. There is also a short-cut for the tools with CRTL+1 - 0. Using CTRL+1 for instance calls the first defined tool in the tools-menue.