Now, I don't really know why I'm interested in this other than because it's interesting, but I have pretty much every single version of indev and infdev on my computer. I installed them by downloading the jar and json files and putting them into a folder in the versions folder of .minecraft. It usually loads up the title screen, but as soon as I try to generate a world, depending on the version, it will either give me an in-game error, return to the title screen, or go black. I heard that it could have been the new launcher, so I downgraded to the old launcher, but that didn't work either. I remember being able to play these versions with the new launcher a while back, but now it isn't working for some reason.