Your custom launcher is running an old version.
At first glance, this error message—often encountered when trying to join a server or launch a mod—is infuriating. It implies that your game is outdated, that you need to download a specific, older patch, and that the "current" version of the game on Steam isn't good enough. It feels like a step backward. assetto corsa is obsolete v1.16.3 is required
This error almost always occurs when you are using to install the Custom Shaders Patch (CSP) . Because Assetto Corsa is a title that relies heavily on its community—with ongoing third-party graphical and physics overhauls—the game's core files and the mods you run must be in total synchronization. Your custom launcher is running an old version