I'm trying to use the currently recomended FML version (currently 22.214.171.124) which claims to be an acceptable modloader replacement. I'm trying to use it with http://www.minecraftforum.net/topic/1414578-132-essentials-v05/ this mod, and it throws an error.
I've put my crash report in the spoiler.
A similar crash happens even when it's just Forge and Essentials. Another mod that seems to have trouble is Pfaeff's Mods http://www.minecraftforum.net/topic/200272-v124-pfaeffs-mod-ssp-v100-allocator-jump-pad-and-more/