lvra.gitlab.io/content/docs/vrchat/eac.md
hypevhs e5276b5b70 VRChat EAC: Rewrite
EAC startup errors are really rare now. Let's write the article in the
past tense.
2025-04-25 18:38:38 -05:00

4.3 KiB

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50 Easy Anti-Cheat

Easy Anti-Cheat

Running VRChat on Linux used to be prone to unwarranted EAC errors. Sometimes, seemingly randomly, you would get an EAC error during the VRChat startup/login screen. It looks like a message box, with the title "Anti-cheat Error", a message referring to a filepath that failed to validate integrity, and a single button labeled "Quit". This would trigger even when all files were unmodified.

Thankfully, at some point in October or November 2024, these EAC errors resolved themselves. While it is still possible to get EAC errors for other reasons, the race condition that made it a coin-flip on startup no longer plagues us.

If you are running into EAC errors still, try these options:

  • Trigger a reinstall of the EAC runtime by moving the Proton prefix for VRChat somewhere else, forcing Steam to regenerate it on next launch
  • Make sure you are not blocking the EAC domains, such as modules-cdn.eac-prod.on.epicgames.com
  • Do not set SDL_VIDEODRIVER env var anywhere - this breaks the splash screen
  • Do not use the VR_OVERRIDE env var

The below workaround shouldn't be necessary anymore, but is kept here in case the issue comes back someday.

Workaround

Wrapper script for starting VRChat: startvrc.sh on GitHub

Set startup options for VRChat: /path/to/startvrc.sh %command%

If you're using extra env vars, they should go first: PRESSURE_VESSEL_FILESYSTEMS_RW=/run/user/1000/monado_comp_ipc /path/to/startvrc.sh %command%