NS_S_WMR_ALREADYRENDERED (0x000D105F) Fix

You're playing a video in Windows Media Player 12 on Windows 10 or 11, and suddenly playback stops. You check the event log or a developer console and see NS_S_WMR_ALREADYRENDERED (0x000D105F). This happens most often in Remote Desktop sessions or when you've got a web page that embedded a media player and keeps calling the render function twice. I've also seen it in old Silverlight apps that try to play a stream that's already rendering.

Root Cause

The error code says it all: the stream was already rendered. Windows Media Player's streaming engine can only render a stream once per playback session. When something triggers a second render request — like a JavaScript timer firing twice, or a redirect loop in a web app — the engine throws this warning. It's technically a success code (NS_S is warning, not error), but it blocks further playback unless you reset the state.

Fix 1: Reset Windows Media Player Settings

1. Close Windows Media Player completely. Check Task Manager for wmplayer.exe and kill it if it's still running.
2. Open Command Prompt as Administrator. Click Start, type cmd, right-click, Run as administrator.
3. Run this command:
   

   reg delete HKCU\Software\Microsoft\MediaPlayer\Player /f

   This wipes your WMP user settings. Don't worry, it doesn't delete your media files.
4. Restart WMP. It'll rebuild the registry key fresh. Try playing the file again.

Fix 2: Check for Script Loops

If the error happens inside a web browser (like Internet Explorer or an old Edge), the culprit is almost always a script that calls player.play() twice. Open your browser's developer tools (F12), go to the Console tab, and look for repeated play commands. Fix the script so it only calls play() once after the stream is ready. In JavaScript, that means wrapping it in a check like:

if (player.playState !== 3) { player.play(); }

Don't bother with browser cache clears or reinstalling media codecs — they rarely help here.

Fix 3: Disable Hardware Acceleration

Sometimes the GPU driver gets confused. Turn off hardware acceleration in WMP:

1. Open WMP. Press Alt+M to show the menu bar.
2. Go to Tools > Options > Performance tab.
3. Under Video acceleration, slide the bar to None.
4. Also uncheck Use DirectX Video Acceleration if it's enabled.
5. Click Apply and restart WMP.

If It Still Fails

Check if you're running Windows Media Player through Remote Desktop. I've seen this error a lot when RDP redirects audio and video. Go to your RDP client settings and try disabling multimedia redirection. Also check if your antivirus is blocking WMP's streaming engine — temporarily disable it to test. If nothing works, switch to VLC or MPC-HC. They don't have this narrow limitation.