NS_E_WMPCORE_PLAYLIST_ITEM_ALTERNATE_EXHAUSTED (0XC00D10A0) Fix

This error is annoying, but the fix is simple

You're trying to play a file in Windows Media Player (WMP) and you get hit with NS_E_WMPCORE_PLAYLIST_ITEM_ALTERNATE_EXHAUSTED (0XC00D10A0). The player stutters, maybe hangs for a few seconds, then spits out this error. I've seen it most often on Windows 10 21H2 and 22H2 when playing an MP4 or MKV file that uses a less common codec like AAC Latin or AC-3 audio. What's actually happening here is WMP runs out of built-in alternate stream handlers—it can't find another decoder to try, so it gives up.

The real fix: clear the WMP library database

Skip all the driver updates and codec pack suggestions you'll find elsewhere. They don't touch the root cause. What you need to do is reset WMP's internal playlist and metadata cache. That database gets corrupted over time—especially if you've added and removed media folders, or if you have files with broken metadata.

1. Close Windows Media Player completely.
2. Open the Run dialog (Win+R) and type: %LOCALAPPDATA%\Microsoft\Media Player
3. Delete everything inside that folder. Don't worry—Windows will recreate the database the next time WMP starts.
4. Now restart WMP. It'll scan your monitored folders again and rebuild the library from scratch.

That's it. The error should be gone. If you're on Windows 11, the folder path is the same—Microsoft never moved it.

Why this works

The database at %LOCALAPPDATA%\Microsoft\Media Player stores metadata about each file: codec info, alternate streams, playlist positions. When you add a file that has multiple audio tracks (say, an MKV with English and Spanish AC-3 streams), WMP writes an entry for each alternate stream into the database. If that entry gets corrupted—maybe the file was partially downloaded, or you edited metadata outside of WMP—the player tries to switch to an alternate stream that doesn't actually exist anymore. It runs through all available alternates, fails on each, and throws 0XC00D10A0 because it's exhausted all options.

Deleting the database forces WMP to re-query every file from scratch. It re-reads the actual headers, builds fresh alternate stream entries, and verifies they exist before marking them as playable. No more phantom alternates.

One caveat: you'll lose your playlists and play counts. If that matters, back up the current database_* files first, then restore them after clearing the rest. But honestly? I'd just rebuild them.

Less common variations that still point to the same root

Sometimes the error appears only when streaming from a DLNA server. That's because the server reports alternate streams that don't match the actual file. In that case, try re-adding the media folder: right-click in WMP, choose Manage Libraries, remove the folder, restart WMP, then add it again. That triggers a full rescan without deleting the database—less destructive, but might not work if corruption is already in the DB.

Another variation: you get the error on a single file but not others. That points to a codec mismatch. WMP on Windows 10 uses the Media Foundation framework, not the old DirectShow codecs. If you installed a codec pack like K-Lite, it sometimes breaks MF's ability to enumerate alternates. Uninstall the codec pack, then run sfc /scannow to restore MF components. Then reinstall a minimal codec pack (I recommend the "Mega" variant of K-Lite, but only the MF-focused components).

Third scenario: the file is DRM-protected and the license is expired. WMP tries to find a valid alternate stream (like a lower-bitrate version) and fails. There's no fix besides renewing the license or removing DRM (which I can't help with). But you can rule this out by playing the same file in VLC Media Player. If VLC plays it fine, it's a WMP-specific DRM issue, not a database problem.

How to prevent it from coming back

Three things:

• Don't edit metadata outside WMP. Tools like MP3Tag or TagScanner rewrite file headers that WMP doesn't expect. If you must edit metadata, use WMP's built-in editor (right-click file, Advanced Tag Editor).
• Avoid partially downloaded files in monitored folders. WMP indexes them immediately, writes incomplete alternate stream info, then when the download finishes, the alternates shift. Use a separate "Incomplete" folder outside WMP's library.
• Regular database maintenance. Every few months, stop WMP and delete just the current database_* files (not the entire folder). The player rebuilds them on next start, and you keep your playlists.

If you follow those, you'll probably never see 0XC00D10A0 again. And if you do, you now know the quickest way out.