Why? Because v1.1.63 allowed asymmetric tire heating , dynamic brake duct simulation , and chassis flex on open-top cars —features later versions neutered for console compatibility. Today, if a mod has .dds textures with the metadata Pirelli_2015 or uses the encrypted tyres_v1163.ini , your modern v1.16.4 Assetto Corsa will scream
The error we just fixed is a false positive caused by the game and CSP. However, Content Manager has a different, legitimate feature for dealing with outdated cars. assetto corsa is obsolete v1163 is required fix