NS_E_MLS_SMARTPLAYLIST_FILTER_NOT_REGISTERED: Fix 0XC00D1075

When This Error Hits

You're trying to play a music file or sync a playlist in Windows Media Player 12 on Windows 10 or 11. Suddenly, a pop-up says "An error occurred while creating or updating the playlist" with the code 0XC00D1075. In the Event Viewer, you'll see the message NS_E_MLS_SMARTPLAYLIST_FILTER_NOT_REGISTERED. This usually happens after a Windows feature update (like the 22H2 update) or after you install a third-party media app that overwrote some system files.

What's Really Going On

The smart playlist feature in WMP relies on a COM filter called wmp.dll that registers itself when you first launch the player. If that registration gets corrupted (by an update, a registry cleaner, or another app), the player can't parse the playlist rules anymore. It's not a hardware problem, and it's not a network issue. You don't need to reinstall Windows. The fix is a simple re-registration of that filter.

The Fix: Re-register the Smart Playlist Filter

1. Close Windows Media Player completely. Check the system tray for any leftover WMP icons. Right-click them and choose "Exit". If you skip this, the next step will fail.
2. Open Command Prompt as Administrator. Click Start, type cmd, right-click "Command Prompt" and select "Run as administrator". Click "Yes" on the UAC prompt.
3. Reregister the filter. Type this command and press Enter:
   

   regsvr32 wmp.dll

   After a few seconds, you should see a popup: "DllRegisterServer in wmp.dll succeeded." Click OK.
4. Also reregister the playlist component. Type this and press Enter:
   

   regsvr32 wmploc.dll

   Again, wait for the success message and click OK.
5. Reboot your computer. A restart isn't always required, but I recommend it to clear any cached state in WMP. After you log back in, launch Windows Media Player and try to play the same file or sync the same playlist.

What If It Still Fails?

If the error persists, one of two things is happening. First, you might be running a third-party codec pack (like K-Lite or Shark007) that replaces the WMP filter with its own version. Uninstall that codec pack, reboot, then rerun the regsvr32 commands above. Second, it could be a permissions issue in the registry. Open Regedit and navigate to HKEY_CLASSES_ROOT\CLSID\{6BF52A50-394A-11D3-B153-00C04F79FAA6}\InprocServer32. Check that the default value points to C:\Windows\System32\wmp.dll. If it's missing or wrong, set it manually, then run the regsvr32 commands again. That's the last stop before a fresh install of the Media Feature Pack, which I've only had to do once in five years.