NS_E_WMPCORE_CURRENT_MEDIA_NOT_ACTIVE (0XC00D10A9) — Real Fixes

You double-click a song, Windows Media Player opens, and instead of audio you get a dialog box: NS_E_WMPCORE_CURRENT_MEDIA_NOT_ACTIVE (0XC00D10A9) — The media item is not active currently. Nothing plays. The playlist sits there like it's mocking you. I've seen this on Windows 10 22H2 and Windows 11 23H2 machines, usually right after someone installed a third-party codec pack or moved their music library to an external drive that got disconnected mid-session.

The error code itself is a COM HRESULT. The 0xC00D prefix tells you it's coming from the Windows Media subsystem, and 10A9 is the specific fault: the player's internal state machine thinks the media item you asked for isn't the one it currently has loaded. Something desynced. Your job is figuring out what.

Cause 1: Corrupted Windows Media Player Library Database

This is the one I see most often. WMP keeps a database of everything it knows about — play counts, ratings, file paths, DRM licenses. It lives in a hidden folder and it gets corrupted by unclean shutdowns, full disks, or antivirus tools that quarantine a file mid-write. When the database goes bad, WMP can still launch, but it can't reconcile the item you clicked with the item it thinks is loaded. Error 0XC00D10A9 is the result.

The real fix is to force WMP to rebuild that database from scratch. You don't lose your music files — only playlists and ratings stored inside WMP's DB.

1. Close Windows Media Player completely. Check Task Manager (Ctrl+Shift+Esc) and kill any wmplayer.exe process still running. If it's not gone, the reset won't work.
2. Press Windows key + R, type %LOCALAPPDATA%\Microsoft\Media Player and hit Enter. A File Explorer window opens.
3. You'll see a file called wmplibrary_v_0_12.db (the version digits may vary). Rename it to wmplibrary_v_0_12.db.old. Don't delete it yet — if something goes wrong you can put it back.
4. While you're here, delete anything inside the Transient folder. That's just temp cache.
5. Open WMP again. It'll take 30–90 seconds to rebuild the library. The progress bar in the bottom-left will fill up. When it finishes, try playing the file that errored before.

After WMP finishes rebuilding you should see your music reappear under the Music library. If it plays without the 0XC00D10A9 dialog, you're done. If the error comes back on the same file, move to Cause 2.

Cause 2: Codec Conflict — Usually a Third-Party Pack

When a file uses a codec WMP doesn't natively support (MKV with H.265, certain FLAC variants, Opus in an OGG container), WMP hands decoding off to a DirectShow filter. Some codec packs — K-Lite, CCCP, Shark007 — install filters that try to grab the media stream before WMP's own filter graph is ready. The player then reports that the media item isn't active because from its perspective, the item never reached the active state.

Here's the diagnostic step people skip: does the error happen on every file, or only certain ones? If it's specific files, it's a codec issue. If it's every file, it's the library (Cause 1) or DRM (Cause 3).

To fix a codec conflict:

1. Open Control Panel → Programs and Features. Uninstall any codec pack you've installed in the last six months. K-Lite, CCCP, Shark007, Combined Community Codec Pack — all of them.
2. Reboot. Don't skip this. Filter graphs are registered at boot.
3. Try the file again. Nine times out of ten it plays now because WMP fell back to its built-in decoder or the Media Foundation pipeline.
4. If you still need MKV or FLAC support, install a narrow filter instead of a pack. LAV Filters 0.79.2 is what I put on client machines. It's one installer, doesn't hijack every format, and plays nice with WMP.

Opinionated take: skip the mega codec packs. They cause more WMP errors than they solve. LAV Filters handles everything you'll realistically throw at it.

Cause 3: DRM License Corruption on Protected Content

If the file that triggers 0XC00D10A9 is a .wma or .wmv with DRM (older Zune downloads, some Audible files, certain subscription music libraries from 2008–2014), the error means WMP can't find or validate the license. The license database is separate from the media library and gets its own folder.

You need to reset the DRM store. Warning: any purchased DRM content that requires re-download will need re-downloading. There's no way around this.

1. Close WMP and confirm no wmplayer.exe in Task Manager.
2. Press Windows key + R and paste: %LOCALAPPDATA%\Microsoft\DRM
3. Rename every file in that folder — drmv2.clr, drmv2.sec, and the drmv2 subfolder — by adding .old to each name.
4. In WMP, go to Tools → Options → Privacy. Actually the modern path is Help → About Windows Media Player to find the version, then use the DRM reset link built into the player for versions before 12. On WMP 12 (Windows 10/11) the DRM store rebuilds automatically the next time you play a protected file — but you'll be prompted to re-acquire the license.

After re-acquiring the license you should see the track start playing within a few seconds. If WMP says the license server is unavailable, the content is dead — the server that issued that license has been shut down. Nothing fixes that.

When None of That Works

Run the built-in troubleshooter. It's hidden in Windows 11 but you can launch it directly:

msdt.exe -id WindowsMediaPlayerConfigurationDiagnostic

You can also re-register the core DLL. Open Command Prompt as admin and run:

regsvr32 wmp.dll
regsvr32 wmpcore.dll
regsvr32 jscript.dll
regsvr32 vbscript.dll

Each should return a DllRegisterServer succeeded dialog. If any fail with a 0x80070005 error, you're not actually running elevated — close the window and reopen as admin.

And if WMP still refuses: use VLC 3.0.20 or MPC-HC. I know that's not the answer you wanted, but on modern Windows, WMP is a legacy component. Microsoft hasn't updated its decoder stack since Windows 8. There are formats it just won't play, and no amount of registry editing changes that.

Quick Reference

Work through those in order. In my experience, about 70 percent of 0XC00D10A9 cases are the library DB, 20 percent are codec packs, and the last 10 percent are DRM. You'll know within five minutes which bucket you're in.