Fix NS_E_WMPCORE_PLAYLIST_ITEM_ALTERNATE_NAME_NOT_FOUND (0XC00D10A1)

1. Missing or renamed playlist file (most common cause)

The culprit here is almost always a playlist file that got deleted, moved, or renamed. Windows Media Player keeps track of playlists by their file path. If that path changes, WMP can't find it and throws this error.

Think about what you did before the error showed up. Did you clean up your Music folder? Move files to an external drive? Delete a bunch of .wpl or .zpl files? That's what triggered it.

The quick fix: Remove the broken playlist from WMP

1. Open Windows Media Player (WMP12 on Windows 10/11, WMP11 on Windows 7).
2. Go to the Playlists section in the left pane.
3. Find the playlist with a yellow warning icon or one you suspect is broken.
4. Right-click it and select Delete.
5. Choose Delete from library only — don't delete the source file if it still exists.

Restart WMP. The error should disappear. If you still see it, the playlist might be nested inside another playlist. Check all your playlists for that warning icon.

If you want to keep the playlist data

If that playlist was important, you can rebuild it. First delete it from the library as above. Then create a new playlist with the same name and add the songs manually. WMP doesn't have an import function for old playlist files, so you'll be doing this by hand.

2. Corrupted WMP library database

If the first fix didn't work, the database that WMP uses to track your media is probably corrupt. This happens more often than Microsoft admits — especially after a crash or forced shutdown.

You can tell if this is your issue because the error shows up randomly, not just when opening one specific playlist. You might also see other errors like 0xC00D11D4 or NS_E_WMPCORE_MEDIA_NOT_FOUND.

Rebuild the library database

Close WMP completely. Then:

1. Open Windows Explorer and navigate to:
   %LOCALAPPDATA%\Microsoft\Media Player
2. Delete any files that start with wmdb. Don't touch anything else in that folder.
3. Restart WMP. It'll rebuild the database from scratch.

This can take a few minutes if you have a large library. The error should be gone when it finishes.

Warning: Deleting the wmdb files resets your play counts, ratings, and last-played dates. You're losing metadata, not your actual music files. If that's a dealbreaker, skip to option 3.

3. Permissions issue on the playlist folder

This one's rarer, but I've seen it on corporate machines with locked-down user profiles. WMP can't read the playlist file because Windows says "no."

The error code is the same, but you'll notice it happens across multiple playlists, not just one. And the playlists you see in WMP show up as empty.

Check and fix permissions

1. Find the playlist file. It's usually in your Music folder or %USERPROFILE%\Music\Playlists.
2. Right-click it, choose Properties, then the Security tab.
3. Click Advanced, then Change Permissions (or just look at the list).
4. Make sure your user account has Read & execute and Read permissions. If not, click Add, select your user, and grant those rights.

Apply the change and restart WMP.

Quick-reference summary

Start with cause #1. It fixes 90% of these errors. If that doesn't work, nuke the database. Don't bother reinstalling WMP — it's built into Windows and that rarely helps. You'd just be triggering a Windows Feature repair, which takes longer and gives the same result as deleting the database.