The game crashed whilst exception in server tick loop
Error: java.lang.ClassCastException: gcewing.sg.rf.RFPowerTE cannot be cast to nc.capability.radiation.resistance.IRadiationResistance

full log: https://pastebin.com/fda5M5Wj

Line 23:
java.lang.ClassCastException: gcewing.sg.rf.RFPowerTE cannot be cast to nc.capability.radiation.resistance.IRadiationResistance

This is an sgcraft bug, and I'm pretty sure I already reported it or something similar to them a while back. It looks like you may be using an old version of the mod - you sure you have one of the latest versions from here?

you sure the fork is legit? i never even knew that site existed.

I'm pretty sure, yes. Probs best to ask the devs, though :)