I am using Windows 7, 64 bit, and I am using Java 7 update 11. I am using my own computer as a host, and am just using localhost for the IP, and everything is port forwarded. I am using the Direwolf20 modpack version 5.0.1. So far I have added no mods to the server. I have just downloaded the Direwolf20 modpack server from the website. Everything is port forwarded, the server starts up fine, it's all going well. When I try and join the server I get this " Forge Mod Loader has found world ID mismatches World: (ModID: Minecraft, type uv, ordinal 2) Game (ModID: Railcraft, type rc.item.cart.furnace or World: (ModID: Minecraft, type uv, ordinal 1) Game (ModID: Railcraft, type rc.item.cart.chest or World: (ModID: Minecraft, type uv, ordinal 0) Game (ModID: Railcraft, type rc.item.cart.basic or You cannot connect to this server" When the "or" part shows up, I cannot see any farther on my screen. On the console it shows me logging in, and then it says I lost connection and I get the message. I am a little bit confused about this, and have tried to look up in the railcraft configs, but I have not found anything weird. Any help would be greatly appreciated.