sometimes I get as far as the main menu but when I open it the mouse arrow turns into a loading circle and says "starbase sim not responding "
hm, I need more info. By default a log file is saved in your user folder, which should be accessible via the following address where you have to replace the username with your name: C:\Users\username\AppData\LocalLow\Ashtorak\StarbaseSim
Please send this file to me or post the content here.
Alternatively, you could create a shortcut of the StarbaseSim.exe and then in its properties add " -logFile log.txt" to the target like shown below. Then if you use this to start the game, it will generate a log file in the same directory called log.txt.