Since 1.10.2 IC2Classic has his own File Structure and is not compatible with IC2Exp Core class access anymore.

This crash comes from one of your mods. I tried to find out which directly but i was unable to find which mod has the classes...

Here is the crash:
http://pastebin.com/nwSF6Tbp

IC2Classic has a second modID where you can detect when it is loaded.
"IC2-Spmod-Classic"
Would be nice if you take care of that.
If you need any help ask.

Since 1.10.2 IC2Classic has his own File Structure and is not compatible with IC2Exp Core class access anymore.

Why are you still using the same main mod id then? I don't think it's a good idea to share modid's with different mods.

Eitherway, it's an easy thing for me to fix in CommonCapabilities, but still, I think you should reconsider your mod id.

Well mainly because of modcompat because even so if ic2c is not ic2exp its still ic2 so using that modid makes actually sense because i support their API sich close systems...

What you could do is a custom sidedProxy which would be the best solution or prevent the load of your ic2 plugin when you detect ic2classic. That's why I have two modids