I just bought the game yesterday and had that weird loading screen bug but I fixed it by changing windows language to English. Eventually I started building something like the ISS.
Today I loaded my save and when I went to VAB to build another module I saw that I cannot launch the spacecraft from the VAB. I can only launch it from the launch pad but the thing is when I try to launch it from the launch pad I cannot revert to launch or revert to VAB. In addition to that bug I can't also quicksave or save. My last save is from yesterday and the game is not autosaving as well. Naturally I'm stuck with no game save and I need some fix.