Recently I was getting the error: game already saving. It only seems to happen when the facility is active, and i have it doing a lot of tasks. So far I have fixed it by limiting the nanites to 200, while slower then it can be with unlimited, it seems to have not interrupted the game while saving which caused the infinite saving error. I have been playing for several hours now and let the NCF construct a huge new mining vehicle ive been building and so far so good. If you are getting this issue try this solution and let me know if it works for you, because if not then it might not actually be working for me. Thanks!