Whenever I try and open world A using the Direwolf20 1.7.10 pack, it will change to the dirt screen, say loading world, and then cut immediately back to the menu. If I try and open world B before trying to open world A, world B will open as normal, but if I attempt to open world A first, no other world will open and kick me back to the main menu. After attempting to open world A, if I close the client and launcher and attempt to open any other modpack, the launcher only let me launch Direwolf20 1.7.10. I have no idea what is causing this and because it does not actually crash the game I don't have an error log.