Linux VR users facing SteamVR error 303 have a driver check to make before changing their headset setup. MIXED reports that Valve traced one such failure to missing Nvidia 32-bit user-space libraries. Valve says the proprietary driver's running kernel module, 32-bit libraries and 64-bit libraries must all be installed at exactly the same version.
Steam opened while the GPU driver setup was broken
The owner opened issue 977 on Valve's SteamVR-for-Linux tracker on September 30, reporting error 303 when launching a game and no compositor logs. Valve replied about 14 minutes later, according to MIXED.
Valve's diagnosis was broader than a SteamVR startup failure. The missing libraries forced Steam to use llvmpipe, Mesa's CPU renderer, and Vulkan was broken across the system. An opening Steam window therefore gave the owner little evidence that the Nvidia driver was working as VR needed it to.
The owner later moved to a 610 driver and reported that the diagnostics stopped naming llvmpipe. By October 1, SteamVR could boot into Half-Life: Alyx, but then hung on a Mongoose timeout. That follow-up shows progress past the original failure while leaving the owner's VR session unresolved.
A separate check from the Nvidia 580 issue
This follows our coverage of Nvidia's 580 branch and Steam Link VR on Linux. MIXED describes that branch incompatibility as a separate issue with a different cause. A PC can have a mismatched driver installation as well as a branch incompatibility.
For error 303, Valve's advice concerns the completeness and exact version match of the installed components. The owner's move to 610 is an individual test result. MIXED reports no patch or announced SteamVR warning for mismatched components, and says the report remains open.
