Can't launching Sonic Generations (2011) with any mod on Steam Deck (Proton)

Hello,

I'm a bit desperate because I love to play/speedrun on Unleashed Project for Sonic Generations. Since few weeks now, I can't play Sonic Generations (2011) anymore when it has mods on my Steam Deck, the game just don't want to launch and crash few seconds after clicking on play. (Still working like a charm on my Windows PC)

The only mod that work as far as i know is Direct3D 11, Sonic Generations runs well on Steam Deck through HedgeModManager. But at the instant I'm adding Unleashed Project and Unleashed Project Low End or only with Jet Set Generations to the config, and then I launch Sonic Generations, the game start (with the right GraphicsConfig.cfg) and then crash, but don't know why because I never changed the config since months.

Both SonicGMI and HedgeModManager goes to the same result when I'm adding more than just Direct3D 11 with any version of Proton. (already tried with Proton Experimental, 10.0 (beta) and 8.0) the game just won't run. And I'm also wondering if this problem does not come from a Steam Deck Update (currently on 3.7.13).

I don't know where to search for help on that issue, so I'm asking here because you might know something at hedge-dev to fix it or to redirect me to the right team or the right person to talk with.

Context (Environment)

• SteamOS version: 3.7.13 (20250630.1)
• Linux Kernel: 6.11.11-valve19-1-neptune-611-g88b36d49a5e3
• HedgeModManager 8.0.0-beta4

Placing here some files that might helps you to understand, both of them just end by pid 50192 != 50190, skipping destruction (fork without exec?) for example :

• (proton-10beta)-steam-71340.log
• (proton-experimental)-steam-71340.log
• HedgeModManager.log

I tried to log the Debug Console from HedgeModManager, but don't found where the outputs are, let me know their locations in order to give you them.

Thank you for your amazing work! 😄

Start by reviewing the attached Proton and HedgeModManager logs, then reproduce the difference between Direct3D 11 alone and the listed mod configurations on SteamOS 3.7.13 with the reported Proton versions. Compare the logs for a clear failure point; done means identifying an actionable HedgeModManager cause or documenting that the failure belongs to Proton, SteamOS, or the game/mods.