I am new to KSP and am attempting to work through the training modules to become familiar with the program. However, in attempting to work through the "Intermediate Training" module, the program locks up. I reach the screen where Wernher von Kerman asks me to switch over the Engine tab and attach the LV-T45 "Swivel" engine. But when I open the Engine tab there are no engines shown. So I can't attach an engine and the "Next" button remains dimmed out and unusable. So I can't go forward and I can't go backwards. My only option is to quit the module and start over, hoping for a different outcome. Which of course doesn't happen! I've tried rebooting the computer and restarting KSP to no avail. Any suggestions on how I can solve this problem? Is there a way I can reload or repair the KSP program without having to again pay for it? Thanks in advance!