VA-DC FLL, I started having troubles with NXT-G v2.0 this summer – during a workshop of course. The program just kept crashing – and generating crash reports. I installed Mountain Lion a couple of weeks ago – same problem. I order a site license for v2.1 and just got the package today – I know have v2.1 installed it on my Mac. I experienced the same "broken file error" that's been described on the listserv over the past couple of weeks. LEGO Tech support folks were very helpful. All I needed to do was put the install disk back in, find the "Parts" folder, and reinstall the "legodriver.pkg". NXT-G works perfectly now. Hope this helps if you have a similar problem. BTW, the BIG benefit to v2.1 is that the tutorials now work on the Mac. Good luck this season! Nick -- To UNSUBSCRIBE or CHANGE your settings, please visit https://listserv.jmu.edu/archives/vadcfll-l.html and select "Join or leave the list". -- VADCFLL administrative announcements are sent via VADCFLL-ANNOUNCEMENTS-L. Visit https://listserv.jmu.edu/archives/vadcfll-ANNOUNCEMENTS-l.html to subscribe.