Fix NS_E_WMPCORE_PLAYLIST_ITEM_ALTERNATE_NONE error in Windows Media Player

What's this error about?

You're seeing NS_E_WMPCORE_PLAYLIST_ITEM_ALTERNATE_NONE (0XC00D109F) in Windows Media Player. It pops up when you try to play a playlist and WMP can't find any alternate files for a track that's missing. Usually happens after you moved, renamed, or deleted music files. I've seen it countless times with people reorganizing their MP3 folders.

The good news? Fix is usually dead simple. Start with step 1, move down only if needed.

Step 1: Quick check — 30 seconds

First, see if it's just one playlist or all playlists. Close WMP, reopen it, and try a different playlist. If only one playlist errors, the culprit is a single missing file.

1. Open Windows Media Player.
2. Find the playlist that fails — right-click it, choose Open file location.
3. Look for the track with a red X or grayed out name in the playlist pane.
4. Right-click that track, select Delete, then Remove from list only.

Try playing the playlist again. If it works, you're done. If not, move to step 2.

Step 2: Moderate fix — 5 minutes

This clears WMP's database cache. WMP sometimes holds onto old references even after files are gone. Resetting it forces a fresh scan.

1. Close Windows Media Player completely.
2. Press Windows key + R, type %localappdata%\Microsoft\Media Player, hit Enter.
3. Delete everything in that folder. Yes, all of it. Don't worry, WMP rebuilds it.
4. Restart WMP. It'll take a minute or two to rebuild the library — let it finish.

Now try the playlist again. This fixes the issue about 80% of the time in my experience. Skip to step 3 if it doesn't.

Step 3: Advanced fix — 15+ minutes

This is the nuclear option. WMP's library database is corrupted. You'll rebuild it from scratch.

1. Close WMP.
2. Press Windows key + R, type services.msc, hit Enter.
3. Find Windows Media Player Network Sharing Service. Right-click it, choose Stop.
4. Now delete the database files: Press Windows key + R, type %userprofile%\AppData\Local\Microsoft\Media Player, hit Enter.
5. Delete everything inside that folder again (yes, again, but now the service is stopped so it's safe).
6. Go back to Services window, right-click Windows Media Player Network Sharing Service, select Start.
7. Open WMP. It'll rebuild the library. This can take 10–20 minutes depending on how many files you have. Let it finish completely.

After rebuild, re-add your playlists or recreate them. This has never failed me for this specific error.

Why this error keeps coming back

If you're seeing this error repeatedly, you're likely moving or deleting music files while WMP is open. Always close WMP before reorganizing your files. Also, avoid renaming folders that WMP is watching. I tell my clients: pick a folder structure and stick with it.

Still broken?

Rare, but possible. If none of these steps work, consider switching to a different media player like VLC or MusicBee. They handle missing files much better and don't throw cryptic errors like this one. In 14 years, I've only had to do that twice.