Hi, I basically registered just to get some help with this problem. It's been bugging the hell out of me for the past hour or so, and I can't seem to solve it.
So, I'm using:
Minecraft 1.4.7 SMP
MinecraftForge v22.214.171.1249 (installed directly in minecraft_server.jar)
GuiAPI-0.15.2.jar (in coremods folder)
I was initially trying to get Mo'Creatures to work. However, GuiAPI seems to be giving Forge problems.
And of course it works just fine when I delete the GuiAPI jar file. There are no mods in the mods folder, either. Just GuiAPI in coremods.
Any enlighment would be dearly appreciated. I'm pulling my hair out over this. x(