Proton Experimental fixes Darktide windowed mode, Deep Rock Galactic input, adds ArcheAge Chronicles

Valve released a minor Proton Experimental update on November 14, 2026, addressing compatibility issues in several Windows games running on Linux. The update makes ArcheAge Chronicles fully playable, resolves a windowed mode failure in Warhammer 40,000: Darktide, eliminates mouse-click hitching in Deep Rock Galactic, and corrects color distortion in VRChat news videos.

Proton Experimental serves as Valve's testing branch for future stable Proton releases, with Proton 11.0-2 currently stable and a Proton 11.0-3 release candidate in progress. These targeted fixes continue Valve's pattern of incremental compatibility improvements for Steam Deck and desktop Linux gaming.

What changed in this Proton Experimental build

• ArcheAge Chronicles: Previously unplayable on Proton; now launches and runs, marking a new compatibility milestone for this MMORPG.
• Warhammer 40,000: Darktide: Fixed a windowed mode regression where the game would fail to display or function correctly when not in fullscreen.
• Deep Rock Galactic: Resolved input-related stuttering triggered specifically by mouse clicks, improving frame pacing during gameplay.
• VRChat: Corrected a video playback artifact causing wavy color distortion in the application's news video feeds.
• Release context: Follows the November 10th Experimental update and precedes the anticipated Proton 11.0-3 stable release candidate.

Why it matters

These granular fixes demonstrate Valve's continued investment in Proton as a production compatibility layer, directly benefiting Steam Deck owners and desktop Linux gamers who rely on Proton Experimental for timely patches before stable channel availability. The ArcheAge Chronicles addition expands the catalog of verified MMORPGs on Linux, a genre that has historically faced anti-cheat and launcher compatibility hurdles.