Problem dragging and dropping album into my A45 Walkman

[sonrac21]

I've dragged and dropped music albums into my A45 Walkmans SD card and all but one have landed correctly.  One of the  albums however has gone into a folder marked Unknown. Depite trying several times to place it into the alphabetical list it still lands in the unknow folder. I have used the same method for years and have never faced this problem before.

Why? What am i doing wrong? Thanks in advance for any help that can be given.

[Lord_viridis]

Check the tags on the songs within the folder.

If using a pc, right click on any song, and go to details.

Check artist info and album.

If it comes up with unknown, that's why.

You may need to change the info in the tags on all/one/some of the files