An increasing number of users have been getting false positives on this game from their antivirus software. To reduce this problem, I've just pushed a patch that strips UPX compression from the executables. This should make no difference at all to gameplay, but should cause fewer false positives and quarantines, which tend to appear as the game not installing, not starting, or crashing while trying to build gameworlds. I apologize for the inconvenience. Pre-patch BuildID: 2805653 Post-patch BuildID: 2913540