Why garrys mod haven't a VAC bans?

Garry's mod VAC is not really the best so that's probably why.

hello my friend was VAC ban on garrys mod. HE don't cheat and don't do anything, just an error and now he can't play on the server qui sont protg by vac

well it still can be used but if you use external hacks that will give you a chance... but lua scripts, with them you have no chance of getting a vac ban...

My guess would be because of some lua / scripts that might cause VAC to respondto ban a person for false positives.

There is VAC but it has been very outdated for along time so most cheats now it does not Detect.

VAC bans carries over to other Valve games, getting one from Garry's Mod would occur way too often because people use allowed scripts.

Just Because it was made to be a sandbox game not a comp game

because they have anti cheat on servers so if they cheat they will be banned on 99% of good servers

Almost everyone would get banned from garry's mod if there was vac because of all the scripting

There's most addons that modifying game. Example is "Aimbot Gun" what adding aimbot to you gun. It's not cheat but if VAC will work this will be detected as cheat and ban for using addon.