I have looked into this problem and apparently, lots of other people have had the same problem. I start revelation in 3.4.0, the newest version, and there were 2 problems. The first problem was that it wouldn't even launch if the launcher was onscreen, and second, it would load a few mods, then crash to the Minecraft launcher. The other threads that I have read are out of date and have broken links so I'm asking the question here.