Ive found out the problem for me atleast. Try to download the most recent Kopernicus mod https://github.com/Kopernicus/Kopernicus/releases/tag/release-1.3.1-3 and put both folders in the zip file in the GameData folder. The Kopernicus mod that comes with RSS is outdated and will not work. This worked for me and I wish you luck for it to work for you as well.