Some mods have their own internal version check written into encrypted Lua scripts. The mod creator may have locked it to a specific CSP version, not just the AC version.
Method 1 – In-game
Launch Assetto Corsa normally → go to Options → General → version shown at bottom right.
Method 2 – File properties
Right-click assettocorsa.exe → Properties → Details → Product version. assetto corsa is obsolete v1.16.3 is required fix
Method 3 – Content Manager
It shows the game version in the top bar or under Settings → Content Manager → About.
If it’s not 1.16.3, the error is legitimate. Some mods have their own internal version check
There are three common culprits:
To understand the fix, one must first understand how Assetto Corsa is developed and distributed. The PC version of the game relies heavily on Steam for content delivery. Over the years, developer Kunos Simulazioni released numerous free updates and DLC packs (such as Dream Pack 1, 2, and 3). There are three common culprits:
The v1.16.3 update was a pivotal moment in the game's lifecycle; it introduced the Laguna Seca circuit and various vehicle physics updates. Because the game’s architecture links the core executable with the content libraries, if your game version (the executable) does not match the version of the content currently hosted on the Steam servers (the libraries), the game cannot launch. The "Obsolete" error is simply the game’s way of telling you that your installed files are older than the current standard required by the server.
This most frequently happens to users who have installed the game from a disc, downloaded a backup from a friend, or inadvertently prevented Steam from automatically updating the game.
Reinstall Custom Shaders Patch (CSP) if you use it — outdated CSP can also cause false obsolete errors.