Well, I used "Locate Missing Files..." and my problem cleared up. And it hasn't come back so far. Sorry I didn't reply sooner. But on the bright side, I have another question I will submit. Thanks for your help.

Did you verify the Path in MMW with the Path in File Explorer? Are they matching? Do the same files also fail when you open them from File Explorer with MediaMonkey?

Lowlander, Thank You for getting back to me.
None of the situations in the link you provided apply to me as far as I can tell. This drive has been in use for several years and up until yesterday, I have never had this problem. The only thing different in the past year is I purchased MMW5 Gold and used it a few times but have gone back to 4. Could 5 have caused this on the older edition? Weird. My big concern is my drive could be failing but I haven't found any thread where this action by MMW4 precludes a drive failure so I guess I will just have to hope for the best here.

Please see: https://www.mediamonkey.com/support/kno ... s-to-play/

I have a question about MMW4 skipping whole albums. It didn't do this for years and now when a song in the album is selected either by right-clicking the menu or double-clicking the song, MMW will start going down the remaining list, turning each song grey without playing until it reaches the end of the album then moves onto the next album.
I read several threads about this problem but nothing that is close to what mine does. One mentioned "Locate moved/missing files". So when I do this MMW will reestablish missing music. All FLAC. All worked in the past. No "virtual drive" stuff or anything else exotic. Just music on HDD. No error messages or anything like that.
Any suggestions?
Thanks to anyone who can help!

plain