Hey everyone! I recently updated to Windows 11, and now I'm having trouble playing many of my MP4 files in Windows Media Player. I get an error saying, "We can't open video. It uses unsupported encoding settings. 0xC00D3E84." I tried opening some of these videos in VLC, where they work fine, and it shows the codec as H264 - MPEG-4 AVC (part 10) (avc1). A month ago, these videos were playing without any issues, so I'm not sure if this is entirely due to the upgrade. Interestingly, some videos have the same codec and still work in Windows Media Player, which has me questioning whether it's truly a codec issue or if there's something else going on with the player itself. I also tried installing the K-Lite codec pack (mega), but even after a full restart, the issues persist. The codec "x264vfw - H.264/MPEG-4 AVC codec" shows up as installed, but it hasn't resolved the playback problem. Here's some additional info: OS Build: 26100.6584, Edition: Windows 11 Pro, GPU: NVIDIA GeForce RTX 2070 SUPER. I've also made sure my Windows and graphics drivers are up to date. Any suggestions?
3 Answers
K-Lite Codec Pack has been outdated for quite a while now. You might want to check out newer codec solutions or alternatives to see if they can play those MP4s correctly.
Before diving deep into codec stuff, make sure your videos are on the right drives. Sometimes external drives can cause these issues. You could also try converting the video using VLC itself; it does a decent job.
The problem happens regardless of whether the files are on my SSD or hard drive. I haven’t tried an external drive yet, though.
It might help to share the video info using a tool called MediaInfo. There are many types of H.264 codecs, and some might not be supported by default. This can help pinpoint the issue with your specific videos.
Here's the codec info I got from VLC:  Any insights?
Is there a specific codec pack you'd recommend?