Fix NS_E_WMP_UI_OBJECTNOTFOUND (0XC00D0FE5) Error

This Windows Media Player error pops up when a UI object referenced by attributes doesn't actually exist. The fix is straightforward — clean the corrupted library or rebuild the player's config.

You'll see this error most often when you're trying to play a media file from a network share or an external drive, and Windows Media Player chokes. The exact message reads something like "Attributes were specified for the %s object, but the object was not available to send them to." That placeholder is usually a file path or URL. The error code is 0XC00D0FE5.

What's actually happening here is that Windows Media Player's internal database — its library cache — has a reference to a UI object (like a playlist entry, album art thumbnail, or metadata field) that no longer exists on disk. The player tries to write attributes to that object, finds nothing there, and throws this error. It's a stale pointer problem, not a hardware failure.

The reason it happens more on network shares or removable drives: those connections drop or paths change, and WMP doesn't handle the missing objects gracefully. It just keeps the old reference and panics when something tries to update it.

Fix: Clear the Media Player Library Cache

Skip reinstalling WMP — that never fixes it. The real fix is to nuke the corrupted database files and let Windows rebuild them from scratch. Here's how.

Close Windows Media Player completely. Check Task Manager to make sure wmplayer.exe isn't running in the background. It sometimes hangs there.
Open the library folder. Press Win + R, type %LOCALAPPDATA%\Microsoft\Media Player, and hit Enter. That takes you straight to the database files.
Delete everything in that folder. Select all files and folders inside (Ctrl + A), then hit Delete. Don't worry — these are caches, not your actual media files. Windows will regenerate them next time you start WMP.
Clear the thumbnail cache too. Open %LOCALAPPDATA%\Microsoft\Windows\Explorer and delete any files named thumbcache_*.db. This gets rid of corrupted album art thumbnails that can trigger the same error.
Restart Windows Media Player. When it opens, it'll rebuild its library. This can take a few minutes if you have a large collection. Let it finish before doing anything else.
Re-add your media folders. Go to Organize > Manage Libraries, remove any network or external drive paths that might be flaky, then add them back fresh. This ensures WMP doesn't pick up old dead references.

If It Still Fails

Two things to check:

Corrupted media files. A single damaged MP3 or WMA file can cause this. WMP tries to read its metadata, fails, and leaves a broken object behind. Use a tool like ffprobe to scan your library for files that throw errors. Delete any that are clearly toast.
Windows Media Player version. On Windows 10 22H2 and later, WMP is deprecated in favor of the Media Player app from the Microsoft Store. If you're still using the old WMP, consider switching. The new app handles missing objects more gracefully — it just skips them instead of crashing.

If you're stuck on an older OS (Windows 7, 8.1), run sfc /scannow from an elevated command prompt to check for system file corruption. I've seen a corrupt wmploc.dll cause this exact error. The SFC command fixes that.