If the error persists, your shaders patch might be the bottleneck:

: Use the Steam Library to right-click Assetto Corsa, select Properties > Installed Files , and click Verify integrity of game files . This ensures you actually have the latest official version. Content Manager & CSP Troubleshooting

Make sure you aren't opted into any old 'Beta' branches in the Beta tab." Option 2: The "Short & Punchy" (Best for Server MOTD) VERSION ERROR: Your AC build is obsolete. v1.16.3 is required