having issues with my custom modpack

[PusillanimousKiwi]

The Modpack works fine in single player or lan games, but once I switch to the dedicated client it crashes on launch. 

log part 1.txt

part 2 of the log: https://pastebin.com/mCd3aZWQ

[JaariAtmc]

UCE defaultkeys{1.0.24} [Default Keyconfig] (defaultkeys-mc1.7.10-1.0.24.jar)

Have a guess what this is and why it won't work on a server.