Anon it sounds like you have my old problem. What I did, was I made sure I had a strong internet connection. Then, I uninstalled again. Finally, I took a file manager app and went to /storage/emulated/0/Android/data/ and I deleted com.StefMorojna.SpaceflightSimulator. I tried again and after installation I built a small meaningless rocket, crashed it, recovered it, and when I was taken back to the main menu it turned out the expansion was back. There are three scenarios in which the above won't work: extremely weak internet connection; iPhone, or a hack. The first is generally easily fixed. The other two are a bit problematic. iPhone does not give access to deeper files, and a hack is riddled with problems from the word go. We are absolutely against it.