Known issues included with the readme in Ryder25 installer package: Thread - Grid 1.3 AnyCar AnyTrack Mod for Race Driver: Grid

Problem: Savegame file is corrupt or will not load after uninstalling mod.
Solution: You left a career event still in process , then uninstalled mod.To fix this error you must reinstall mod, start game up and goto career mode, you will be asked to continue or quit event,quit the event. Exit game then uninstall mod. Your stock game should load fine with no savegame error.

Problem: Savegame file is corrupt or will not load after uninstalling mod.
Solution: You left the Porsche in your garage then uninstalled mod.To fix this error you must reinstall mod, start game up and goto career mode, select any other car besides porche to be sitting in the garage. Exit game then uninstall mod. Your stock game should load fine with no savegame error.

Ryder25 Multi Mod Installer:
Problem: Cannot get mod installer to work at all.
Solution: You will need to manually Install mod. Open windows explorer to your "Grid" game folder, then copy and paste in all mod folders found in the "GhostMod" folder from the mods winrar archive. To go back to the stock game, you would do the same process for the "Original files just in case" folder.

Porblem: The mod installer makes backups of the mod files.This can happen when using/trying different versions of the mod (beta testers for example) and forgetting to uninstall the mod before installing the next/current version.
Solution:Uninstall the mod , copy and paste in the Original stock files back into game from the "Original files just in case" folder. Then reinstall the mod and it will back up original files correctly.