Server won't start

[Captaindrake93]

Launcher/pack Version: 2.1.1

Operating System: Bought a server on Sleek servers and aren't quite sure.

Version of Java: 1.7

Description of Problem: Server wont come online!

Error Messages: [sEVERE] Unexpected exception

java.lang.RuntimeException: ModLoader has failed to initialize.

[sEVERE] Unexpected exception

java.lang.UnsupportedClassVersionError: net/minecraft/server/mod_IC2AdvancedMachines : Unsupported major.minor version 51.0

[sEVERE] Unexpected exception

java.lang.RuntimeException: Exception occured in ModLoader

Link to pastebin of log:

http://pastebin.com/mfZN2GeQ

I dont know what to do :|

[DragnHntr]

Top sticky: Topic: *FIX* mod_IC2AdvancedMachines : Unsupported major.minor version 51.0