Trying to play the 2019 Fe cars (been using them for ages) to find the engine brakes as soon as I touch the gas, and then I found the 2018 formula e mod doesn't seem to be in the car selection page? is anyone else having these issues?
These mods are S397 content on steam.
There's two ways you can repair mod and/or rFactor in general.
For all things you can verify the files installed by opening the Steam app, Right click on rFactor/Properties, Local files. Second from the bottom, Verify integrity of Game Files. This will search through your complete rFactor install, Game files and game code to replace, repair any broken files.
Second is for just the mods alone if your sure it's just them that's at fault, you can unsubscribe in steam, Run rFactor launcher will uninstall the mods, Then close the launcher and re subscribe. Allow stem to re download the mods, Run the launcher and the mods will install completely new.
You will retain any setting like setups. These are store away from the primary mod files and are not deleted when the mod is uninstalled.