Proton Experimental update fixes ARC Raiders and other Linux game issues

Valve has released a new Proton Experimental update for Steam Play, with fixes aimed at several Windows games running through Proton on SteamOS and Linux. The October 15 build addresses a rare crash in ARC Raiders, a crash regression affecting Command & Conquer: Red Alert, Counter-Strike and The Aftermath, plus a controller hotplugging regression in Chrono Trigger. It also marks Breadbox as now playable. ¹²

What changed in Proton Experimental

Proton is the compatibility tool Valve uses to help Windows games run through Steam Play on Linux. It creates a separate Proton prefix for each game: a Windows-style environment where configuration files and, in some cases, saved games and other technical data are stored. That means a Proton update can improve a game without changing the game itself, while also affecting the files and settings around its installation. ¹

Valve's official changelog lists the new Breadbox compatibility status alongside the crash and controller fixes. The ARC Raiders change is described as a rare crash fix, while the Red Alert, Counter-Strike and The Aftermath changes address a regression introduced in an earlier build. The Chrono Trigger fix targets controllers being connected or removed while the game is running. ¹

Why the update matters

Proton Experimental is where Valve tests compatibility changes before they are necessarily folded into a more settled Proton release. For Steam Deck owners and Linux players, that makes it a useful channel for picking up fixes early, although experimental builds can also introduce regressions of their own. Players troubleshooting one of the affected games should check the game's Steam compatibility-tool setting and select Proton Experimental where appropriate, then test the title again after the update is installed.

The update follows another Proton Experimental build from October 12 that addressed a prefix-corruption bug and other issues. That continuing cadence shows how much of the Linux gaming experience depends on compatibility-layer maintenance rather than updates to individual games. ²

Our opinion

This is a practical update rather than a flashy one, but the fixes are well targeted. A rare crash in a current release such as ARC Raiders is exactly the kind of problem an experimental compatibility build can solve, while the older-game fixes make the channel useful beyond the newest Steam releases. The sensible approach is to try Proton Experimental when one of these games is misbehaving, but switch back to a stable Proton version if the update creates a new problem.

Valve's full changelog provides the definitive list of changes, so players should use it as the reference point for any game-specific troubleshooting. ¹