While playing I completed all research I had available. When I went to build a new base I found that I was unable to access all the construction options as they went off the bottom of the screen and I was unable to find a way to scroll down. Specifically, I wanted to add Hangers but they are not visible on the list anymore. (Attached screenshot and save file) Maybe this isn't a bug and I just missed how I scroll down the list, this is the first time I have ever gotten the research that far.