com.valvesoftware.Steam.CompatibilityTool.Proton VS com.valvesoftware.Steam.CompatibilityTool.Proton-GE

I think you are using Steam Flatpak, right? In which case, you're hitting this bug. These games use Microsoft's Media Foundations, and the videos can't play because the proprietary codecs are missing.

The major issue people are having right now is also why Silverblue isn't the "present" of Fedora - namely, Flatpak still has some missing features which lead people to install RPMs instead. RPM-OSTree is a crappy experience for package management - but the solution will be in Flatpak's continuous improvement. Regardless, I have only layered Chrome (and the Fedora Workstation Repositories that provide Chrome) and otherwise I've found that Flatpaks work fine (Steam works fine with the right Flatpaks - just install the community Proton flatpak).

It seems that he is using the version of Proton that is installed from Steam and that is why it gives him failures, he has to use the version of Proton Flatpak if you use Steam Flatpak.

They are fixing MFPlat. Transcoded videos are a fallback. They had a built in local transcoding option (media-converter) but that got dropped as it was causing issues. They are working more towards using local gstreamer/ffmpeg support so they don't have to distribute the codecs. Because there are issues with Codec's and patent blocking and stuff. (https://github.com/flathub/com.valvesoftware.Steam.CompatibilityTool.Proton/pull/48)

If you are running steam via flatpak you need to use this version of proton for anything newer than 5.10

Proton 5.13 introduced sandboxing using Valve's pressure-vessel that wouldn't stack with Flatpak. Users had to install one of the Proton community builds from Flathub (Proton, Proton-Experimental, Proton-GE) or stick with older upstream releases.

I just noticed that even tho I installed Proton GE from Flathub using flatpak install com.valvesoftware.Steam.CompatibilityTool.Proton-GE -y and the repo seems to be updated to the latest version of Proton GE, the version on my system that steam lets me choose is version 7-36.

According to Github issue/PR #126 new builds are failing because of a bug in flatpak-external-data-checker or some incompatibility between the two projects at least.

Are you using the Proton-GE flatpak? I reported this bug here a few days ago: https://github.com/flathub/com.valvesoftware.Steam.CompatibilityTool.Proton-GE/issues/79 Unfortunately the build with the fix failed so no update was published. I ended up uninstalling that flatpak and moved to ProtonUp-Qt to manage my Proton versions

You can also get Proton-GE as Flatpak. I'm using the beta branch & enabled flathub-beta repo for that reason: https://github.com/flathub/com.valvesoftware.Steam.CompatibilityTool.Proton-GE/tree/beta

For Steam, from my testing, the Flatpak version (a way to get the same version of apps on any distro) should work just fine now (Protontricks and Proton-GE are also available on Flatpak). But you should really only install Flatpak version only if you have trouble with normal Steam.

Proton 5.13 introduced sandboxing using Valve's pressure-vessel that wouldn't stack with Flatpak. Users had to install one of the Proton community builds from Flathub (Proton, Proton-Experimental, Proton-GE) or stick with older upstream releases.