First some tech specs out of the way:

• OS: Bazzite
• CPU: AMD Ryzen 5600x
• GPU: Intel Arc A770 16 GB VRAM
• RAM: 32 GB DDR4
• Mesa: 25.2.6

Previously, earlier this year, I had issues like these with Oblivion Remastered. Since then a lot of updates have arrived on Mesa and I've been able to play UE5 games... relatively... well. At least, the graphical issues don't exist anymore. Arc Raiders runs particularly well.

So I decided to reinstall Oblivion Remastered and see if that works without visual problems. But now I can't even launch the game properly!

It consistently crashes 2 or so minutes after launching the game (any Proton version it's supposed to work on, so from 9.0-4 and up, including Proton GE). So this happens when the shader precaching hits around 48%.

At first I thought this was an issue with UE5 shader caching, but after it crashes in the middle of shader precaching it can launch into the game's main menu where... it crashes after about 2 minutes.

This is not an immediate crash; after about 2 minutes the game freezes (the game specifically. My system still works fine), it stays frozen for about a minute, and then it crashes with a UE crash report window.

I've been trying to look for solutions, but I'm only finding reports from earlier this year where the game would crash after an hour or at specific points in the game, nothing that is similar to what I'm experiencing.