... Who told you this? I just kinda figured it out. (Trial and Error) The bug only happens after setting the gamerule, after It's been set and is not changed before you leave the world (Leaving the world saves it) you can no longer start-up any world. It also happens on a clean install (no mods, just the mcp and fml) If I change the randomTickSpeed to anything but zero, it works fine, If I change it to zero but change it to a positive integer before I leave the world, it works fine.
I'm not sure if this is a bug with Forge or MCP but, after setting the gamerule randomtickspeed to 0 Minecraft will load to the menu completely fine, but if I attempt to load into any world it crashes the server side and the client sends me back to the menu saying that I was disconnected from the server, or the client may crash as well. Pastebin of Crash Report: http://pastebin.com/GzPSTA8Y Other Info: I'm compiling with Eclipse WITH NO MODS(other than the 2 default mods) and still getting the crash. I have recreated it multiple times by deleting the project and reinstalling, changing the randomtickspeed to 0, and then quiting and trying to restart Minecraft. As of this post 1.8-188.8.131.526 was the latest version Edit: Also affects the launcher version of Forge_Minecraft_1.8. P.S. I'm aware you can stop the crashes by deleting your Meta-Inf, but still... a bug's a bug.