Unsure what the cause is, can't track it down myself. Here's the log:

http://paste.ee/p/LNoMh

Agricraft Version: agricraft-2.0.0a3
Forge Version: forge-1.8.9-11.15.1.1855-universal

Sorry for the late reply.

Updating Thaumic Infusion didn't help. Though now it isn't exactly crashing. Now it simply sits at a part of loading until it starts Not Responding, no matter how long I leave it there. To double check that it was actually Agricraft, I tried loading up again without the mod installed and I got to the main menu fine. Here's a log: http://paste.ee/p/MQkTM

If you have Thaumic Infusion, update it.

This isn't going to make sense but could you try running the modpack without using MultiMC. I've had multiple instances of crashes like this with MultiMC but it ends up working fine without it.

Edit: Also try updating Forge. That version came out in Feb.

.. I have no earthly idea why that old version of Forge was in there. Hell, I even updated it serverside. Derp. Either way, problem persists on latest forge.

Unsure how to launch without MultiMC, it's a custom pack and I'm not sure how to launch otherwise.

Although trying it again and leaving it for .. quite a long time gave me a slightly new log. Although it's just about it exceeding how much ram I gave it. Doesn't this hint at a memory leak?

Here's the log if it helps at all: http://paste.ee/p/9dq24

you can install forge to the minecraft client from file.minecraftforge.net and drop it in your mods folder which will be located %APPDATA%/roaming/,minecraft

Seems like it ran out of memory before the models even finished loading. My suggestion would be to disable mods one at a time until the error stops.

That or increase the Java VM memory allocation amount.

It's already at 2.5 gigs. I can't really spare any more than that.

Try disabling the splash screen in ../config/splash.properties.

Disabling the splash screen didn't seem to have any effect.

Might be a memory leak...