Did the (OS) drive actually change in Location? If not, remove the C drive, then change the (OS) drive.

Are you saying you don't see Français as option, or it doesn't work when you select this? Which Build (Help > About) of MediaMonkey are you using?

Select the correct drive as Location, then click OK.

Can't say for certain. You'd normally want to fix the old (no drive letter) drive before scanning files in. As you already have C it indicates that you scanned before fixing. This can be a problem if you scanned files you're trying to fix. You can remove the C drive, then fix the (OS) drive.

You need to use Media Properties on the (OS) entry in Location.

You need to wait for the next 2024 beta build for a fix.

Work is still on progress on the next 2024 beta (currently at build 3016), but there have been showstoppers preventing a beta release. This will include an Artwork lookup fix when the next 2024 beta becomes available.

You need to change (OS), it likely is the one with the original files (and files on Playlists).

No, as shown in the screenshot you should see a drop-down for Location. This you click to select the correct drive on your PC.

Select the problem drive in Music > Location node, Media Properties, set to correct drive as Location.

Did you do this for the drive that wasn't working in Location (no drive letter)? You need to fix the 'broken' drive.

There is no update for this for the latest posted 2024 beta build, only an update for 5.0 stable (and there won't be one for 5.1 beta).

Did you click the Location drop down on the Media Properties dialog? You should be able to select your drive there.

Which Build (Help > About) of MediaMonkey and are you using Folder Monitoring or did you use Locate Moved/Missing Files after the files were moved?

Did you use re-assign drive first, and do the files work now? You can't scan before that's the case.