If you are on a "Preview" (paid/Patreon) build, try rolling back to the latest stable public build.
The irony? Your game is actually for CSP to handle. Many players panic when they see this message and assume they need to downgrade their game to 1.16.3, which is a common reaction seen in community forums: "However, after I checked the log file, my AC version is v1.16.4 which is a more updated version than v1.16.3, should I need to downgrade it to 1.16.3 to make it works?" assetto corsa is obsolete v1163 is required fix hot