This error is annoying but easy to kill
You're trying to play a song or video in Windows Media Player and it chokes with NS_E_WMP_UDRM_NOUSERLIST (0xC00D12C0). The file has DRM protection and WMP can't find your user license list. I've fixed this for dozens of users. The fix takes two minutes.
The fix: wipe the DRM folder
Windows stores your DRM licenses in a hidden folder. When that folder gets corrupted — and it does — you get this error. Deleting it forces WMP to rebuild it fresh.
- Close Windows Media Player completely.
- Press Windows key + R, type
%userprofile%\AppData\Local\Microsoftand hit Enter. - Find the folder named DRM.
- Right-click it and choose Delete. Yes, delete the whole thing.
- Empty your Recycle Bin.
- Open Windows Media Player again. It'll recreate the DRM folder automatically.
That's it. Try playing the file now. Nine times out of ten, it just works.
Why this works
The DRM folder holds license data tied to your user account. A corrupted index file inside it — usually Indiv01.key or similar — prevents WMP from reading your license list. Deleting the folder removes the broken index. WMP rebuilds it from scratch on next launch. You don't lose your media files, just the corrupted license cache. Any DRM-protected content you've already purchased will re-download its license the next time you play it (assuming you're online).
Some people try reinstalling WMP or running sfc /scannow. Don't bother. Those rarely touch the DRM folder. The culprit here is almost always that corrupt folder.
Less common variations
If deleting the DRM folder didn't fix it, try these:
1. Reset WMP entirely
Open Control Panel > Programs > Turn Windows features on or off. Uncheck Media Features (which includes WMP). Reboot. Then re-check it. This wipes WMP's configuration including its DRM subsystem.
2. Check for multiple user profiles with DRM
If you use multiple user accounts on the same PC, each has its own DRM folder. The error can show up if you switched users and the license list didn't sync. Delete the DRM folder under each user's %userprofile%\AppData\Local\Microsoft\DRM.
3. Corrupt Windows Media Player database
Rare, but possible. Close WMP. Delete the library database at %userprofile%\AppData\Local\Microsoft\Media Player. Let WMP rebuild it on next launch. This can fix stubborn DRM errors that the first fix didn't touch.
Preventing this from coming back
- Don't force-close WMP. Let it finish its DRM housekeeping when you exit. Hard crashes can corrupt the license cache.
- Keep your media files' DRM licenses current. If a file came from a store that's now defunct (like the old Zune Marketplace), you might be SOL. Consider converting to DRM-free formats.
- Run disk cleanups sparingly. Some third-party cleaners nuke the DRM folder without asking. That triggers the error next time you play a protected file.
- Stick to one user account for media playback. Switching accounts mid-session can confuse WMP's DRM subsystem.
Bottom line: if you see 0xC00D12C0, go straight for the DRM folder delete. It's fast, safe, and fixes the root cause. Don't waste time on system file checkers or reinstalls. You're welcome.