Fix NS_E_WMX_ATTRIBUTE_DOES_NOT_EXIST (0XC00D106E) in WMP

Error 0XC00D106E means Windows Media Player can't find an attribute in its database. The fix is deleting the corrupted library files and letting WMP rebuild them.

You're trying to play a file or edit metadata in Windows Media Player, and bam — NS_E_WMX_ATTRIBUTE_DOES_NOT_EXIST (0XC00D106E). It's annoying because the file plays fine in VLC or MPC-HC. The problem isn't the file. It's WMP's internal attribute database.

The Short Fix: Delete the Library Database Files

Close Windows Media Player completely. Check Task Manager to make sure wmplayer.exe isn't lurking in the background.
Press Win + R, type %LOCALAPPDATA%\Microsoft\Media Player, hit Enter.
Select all files in that folder (Ctrl + A) and delete them. Windows may complain some are in use — skip those for now; we'll handle them next.
Open Task Manager (Ctrl + Shift + Esc). Find any remaining wmplayer.exe or ehshell.exe processes and end them. Then delete any leftover files in that folder.
Empty the Recycle Bin. Then restart Windows Media Player. It will rebuild the library from scratch.

That's it. The error should be gone. If you get the same error on startup, you might need to delete the current database which lives in %USERPROFILE%\AppData\Local\Microsoft\Media Player\ — same folder, different files like currentDatabase_*.wmdb.

Why This Works

What's actually happening here is Windows Media Player stores all your media metadata (artist, album, genre, ratings, play counts) in a proprietary database format — the .wmdb files. These files live in %LOCALAPPDATA%\Microsoft\Media Player.

Error 0XC00D106E means WMP tried to look up an attribute — say, "Album Artist" — but that specific field doesn't exist in its database for the particular item. This doesn't mean the file lacks the tag. The file might have it in ID3 or Vorbis comments. WMP's database just got out of sync. Common triggers: switching between different tagging tools (MP3tag, iTunes), copying media from another user profile, or a Windows update that changed how WMP indexes files.

The reason step 3 works is simple: deleting the entire database folder forces WMP to rescan every media file from scratch. On first launch, WMP sees no database at all, so it creates a fresh one, importing metadata directly from each file's tags. No corrupted records, no stale attribute references.

You might wonder: "Won't this lose my ratings and play counts?" Yes. Those are stored in the database, not in the files. If you care about that data, back up the currentDatabase*.wmdb files before deleting. But most people find the trade-off worth it to kill the error.

Less Common Variations of the Same Problem

Error Appears Only on Specific Files

If the error only shows for, say, FLAC files tagged with MP3tag but not for MP3s, you're hitting a known limitation: WMP doesn't always parse Vorbis comments (FLAC's tag format) correctly. The workaround: strip and re-add the tags using WMP's own editor. Or better, use a tool like Foobar2000 that handles Vorbis comments properly and convert the files to a format WMP likes (AAC, WMA).

Error on Startup Before Any File is Played

This one's trickier. WMP might be trying to load a corrupted playlist or podcast subscription. Delete the Playlists and Podcasts subfolders inside %LOCALAPPDATA%\Microsoft\Media Player along with the database files. Also clear the %USERPROFILE%\Music\Playlists folder. Then restart.

Error Returns After Reboot

This points to a corrupt user profile or a buggy shell extension that modifies the database on boot. Try creating a new Windows user account and see if the error persists there. If it doesn't, your profile's WMP database is toast. You can migrate media files, but you'll have to rebuild the library manually. Alternatively, use sfc /scannow and DISM /Online /Cleanup-Image /RestoreHealth to rule out system file corruption.

Prevention: Keep the Database Clean

Three things will save you from seeing 0XC00D106E again:

Don't mix tagging tools. Stick with one primary tag editor. Jumping between MP3tag, iTunes, and WMP's own editor creates cross-format tag conflicts that confuse WMP's parser.
Let WMP finish indexing. If you close WMP while it's still scanning new files, it can write a partial database entry. Next time it loads, it expects a complete record and throws this error when it finds a null value. Wait for the "Library" bar at the bottom to finish before closing.
Back up your database. Every few months, copy the .wmdb files from %LOCALAPPDATA%\Microsoft\Media Player to a safe place. If the error strikes, restore those files instead of rebuilding everything — you keep your ratings and play history.

One more opinionated tip: if you regularly deal with FLAC or Opus files, stop using Windows Media Player. It's not built for modern audio formats. Use MusicBee or Foobar2000 — they handle metadata properly and don't corrupt their databases every few weeks. But if you're stuck with WMP for work or legacy reasons, the fix above is the fastest way back to a working library.