*blows dust off your PC*
Well, do you have time to screenshot what it says? Or have time to read the error message when it crashes on you? If I could get that it would be easier to explain what to do.
First, try going into the files and deleting "Version.txt" and restart LM, it will come back, maybe you are having the glitch I got maybe 3 or 4 times in 2 years of playing.
Second, try asking a admin with a PM because some people don't post reply' to help posts, if I don't make logical sense here, im tired I literally just woke up and I cant think strait right know,
Lastly, I would delete and reinstall Last Moon, ive had to do that about a million times ^^
Hope this helped, May StarClan light your path!