java.lang.NoClassDefFoundError: net/minecraft/client/entity/EntityClientPlayerMP
at biomesoplenty.BiomesOPlenty.(BiomesOPlenty.java:50) ~[BiomesOPlenty.class:?]

Seems to be a sided error, the rest of the crash report doesn't make much sense though.
Setup is Forge 1024, BoP 670 or 682, on Dedicated server (test environment)

I figured out the cause however, if you comment out/remove PacketPipeline references the server starts without errors. You might need to ask cpw or sirgingalot for help with this, I couldn't find anything obvious wrong with the code.

crash report here anyway.
http://pastebin.com/1bU2TvDT