Official explanations only · checked 18 October 2026

tools/error-codes Error Codes

More on Counter-Strike 2: requirements, patch notes and more.

Counter-Strike 2: 3 error codes explained by Valve, including Disconnected by VAC: You cannot play on secure servers, Competitive cooldown and FATAL ERROR: Failed to on-demand compile shader. Each line gives what Valve says the code means, what it says to do, and a link to its page. No official explanation is published for "VAC was unable to verify", "Matchmaking failed".

Verified 18 Oct 2026

tools/error-codes error codes with official meaning and fix
Code	What it means	What Valve says to do	Source
`Disconnected by VAC: You cannot play on secure servers`	Caused by third-party software interfering with your game or Steam; modifying game files or textures can also trigger it.	Remove custom textures, skin changers or file-modifying software, restart, verify game files; if needed repair the Steam Service, restore boot settings and run sfc /scannow.	Official page
`Competitive cooldown`	Blocks you from Valve servers for a set time after e.g. disconnecting, abandoning, kicking too many teammates, being AFK, griefing reports or VAC-flagged gameplay; it cannot be removed by Support.	Troubleshoot network problems before playing another Competitive match; cooldowns step down by one level after a week of clean play.	Official page
`FATAL ERROR: Failed to on-demand compile shader`	Listed in the patch notes as an error affecting some older GPUs, now fixed; no further explanation.	Fixed, according to patch notes.	Official page updated 30 Apr 2026

No official explanation published for "VAC was unable to verify", "Matchmaking failed", as of 18 October 2026. We do not list unofficial fixes.

Valve help centre

Quick answers

tools/error-codes error questions

What is Counter-Strike 2 error Disconnected by VAC: You cannot play on secure servers?

Caused by third-party software interfering with your game or Steam; modifying game files or textures can also trigger it. Valve says: Remove custom textures, skin changers or file-modifying software, restart, verify game files; if needed repair the Steam Service, restore boot settings and run sfc /scannow.

What is Counter-Strike 2 error Competitive cooldown?

Blocks you from Valve servers for a set time after e.g. disconnecting, abandoning, kicking too many teammates, being AFK, griefing reports or VAC-flagged gameplay; it cannot be removed by Support. Valve says: Troubleshoot network problems before playing another Competitive match; cooldowns step down by one level after a week of clean play.

What is Counter-Strike 2 error FATAL ERROR: Failed to on-demand compile shader?

Listed in the patch notes as an error affecting some older GPUs, now fixed; no further explanation. Patch notes say it has been fixed.

Why is my Counter-Strike 2 error code not listed?

We list only codes Valve explains. As of 18 October 2026, no official explanation is published for "VAC was unable to verify", "Matchmaking failed".

Each meaning and fix is a one-line summary of the publisher's own page, linked on its row. Publishers update these pages; we re-check monthly. All games.