Hello Kyle Thanks for the fast reply! I am installing them through the iniManager. But I have resolved my issue as well. I just remembered that there is a setting in the iniManager which points to the Community Folder. That setting was still for the Microsoft Store version. I did not know, that the Steam version has a different path to the Community folder. After changing that, all my Aircrafts and Airports work now. I am just mentioning this in case, someone else also did this, but forgot that there is this setting. Thanks!