My maps are black!

It sounds like this could be because of a faulty install. To avoid uninstalling/reinstalling you could try to validate the files on steam. To do this find Mini Motor Racing in your Steam Library, right click and select Properties. Select the Local Files tab and then press the verify integrity of game cache.

If this doesn't fix it then I recommend a uninstall and reinstall. Your game should automatically sync to the cloud to save any game data.