Quick answer: Delete or fix the corrupted playlist file (usually a .wpl in your Music folder) or re-sync your library. The error means an attribute like genre or album is blank in the playlist metadata.
This error popped up for me a bunch back when I ran a help desk blog. You'll see it when Windows Media Player tries to read a playlist — often one you imported from an old device or synced from a media server — and finds a field that's supposed to have text but is completely empty. It's not a system crash, just WMP being picky about playlist formatting. The fix usually takes under 5 minutes.
Step 1: Find the problematic playlist
Open Windows Media Player. Look for the playlist that triggers the error. It's usually the one you last tried to open. If you can't tell, go to %USERPROFILE%\Music\Playlists and sort by date modified. The most recent .wpl file is your culprit.
Step 2: Delete or rename the playlist
Right-click the playlist in WMP and choose Delete. Select “Remove from library only” — don't delete the actual files. If you want to keep the song list, rename the .wpl file to .txt first (from that folder), then open it in Notepad. Remove any empty XML attribute values like genre="" or album="". Save as .wpl again.
Step 3: Rebuild the playlist
If deleting worked, just create a new playlist: drag your songs from the library into a fresh list. WMP will generate proper attributes. I've found this solves it 90% of the time.
Alternative fix: Clear the media library cache
If the same error persists after deleting, WMP's cache is probably corrupted. Close WMP. Press Win + R, type %LOCALAPPDATA%\Microsoft\Media Player, and delete everything in that folder. Restart WMP — it'll rebuild the database. This wipes your play history and ratings, but it kills the error dead.
Prevention tip
Don't import playlists from old devices or media servers without checking them first. Open .wpl files in Notepad and look for empty attribute tags like author="". Delete those lines. Also avoid syncing playlists between WMP and iTunes — they handle metadata differently and often create these blanks.
That's it. You should be back to playing music without that annoying pop-up. If you're still seeing it, the file's probably protected by DRM — try converting the playlist to a simple .m3u format instead.