From Rigs of Rods Wiki
- This error is thrown (often with missing d3dx9_29.dll) when certain pieces of DirectX are missing. Please visit the DirectX download site. Do not worry if you think you already have DirectX. The installer will only download and install what it's missing.
- This error was also thrown with a broken .zip file, redownload the file mentioned in the error message.
Too many repeating submesh triangles ??
Some resolutions seem to throw this error, this happens when you change your resolution. (Such as buying a new monitor or changing your native resolution.)
How to Fix
Download the latest DirectX End-User Runtime Web Installer and it will automatically download the newest files and the missing ones.
Run the RORconfig , go into the Render system tab and choose your new resolution.