Video/Audio Playback Issue in QuickLook 4.x.x: WPFMediaKit Fail - Plus a Workaround!!!

• OS Version: Windows 11 25H2
• QuickLook Version: All GitHub .exe or .msi installer versions from 4.0.0 to 4.5.0

Since QuickLook 4, I have been running into a very specific but serious issue: almost all video and audio files fail to play. They used to work perfectly in QuickLook 3. Sometimes QuickLook shows this error:

WPFMediaKit.WPFMediaKitException: Could not render any streams from the source Uri

Other times, it seems to load the audio file, but nothing happens even after clicking the play button.

Because of this severe issue, I had stayed on version 3.7.2 for years. Recently, however, I finally found a workaround.

The trick is to replace the "VideoViewer" plugin from QuickLook 4.x.x with the old plugin from QuickLook 3.7.2.

Here are the steps:

1. Uninstall QuickLook 4.x.x.
2. Install QuickLook 3.7.2.
3. Go to your QuickLook installation folder, for example: X:\...\QuickLook\
4. Open the QuickLook.Plugin folder
5. Copy the folder named QuickLook.Plugin.VideoViewer, and save it somewhere else on your harddrive.
6. Install QuickLook 4.x.x again.
7. Go back to X:\...\QuickLook\QuickLook.Plugin\
8. Delete the existing QuickLook.Plugin.VideoViewer folder from the QuickLook 4 installation.
9. Paste the QuickLook.Plugin.VideoViewer folder that you copied from QuickLook 3.7.2.

After doing this, restart QuickLook, and video and audio playback should work normally again.

Hope this helps. Cheers!

Start by reproducing playback failures on Windows 11 with QuickLook 4.x and inspect the QuickLook.Plugin.VideoViewer plugin where the WPFMediaKit exception occurs. Compare its behavior with the copied VideoViewer plugin from QuickLook 3.7.2, then verify that common video and audio files play in the current installation without replacing the plugin.