Looks Like your missing the 'corvettepclights' file, run the verification through steam. its the one in properties under the rfactor2 install.
Right-click rfactor2 in Steam library, select properties, new window pops up, select local files
Run 'VERIFY INTREGRITY OF GAME CACHE...', it will tell you if you have files missing
Once verification complete, close out the window, steam should start download of missing files
Rerun the verification to comfirn files were downloades and installed
That should do it, close out the properties window and join the server.