Describe the crash
I opened ROTN 2.77.5 through the Twitch launcher (with Optifine) for the first time. The loading screen got stuck on “initialisation: mod pack config checker” and then Minecraft stopped responding. I tried reinstalling without adding Optifine, but got the exact same issue multiple times. I was using java 1.8.0.232 (64 bit) and I had ~5.5 gigs allocated (out of 8) to Minecraft.

To Reproduce
Steps to reproduce the behavior:

1. Download ROTN 2.77.5 through the Twitch launcher. It does not matter if Optifine is also installed.
2. Launch the modpack.

Crash Log
debug.log

Info (please complete the following information):

• Modpack Version: 2.77.5
• Server or Singleplayer: NA (pack did not load)
• Version the world was created on: NA

Additional context
I am using a 2015 13-inch MacBook Pro with 8GB RAM. I usually do not have many issues running modded Minecraft (or vanilla Minecraft, for that matter).

As far as I know, it's just taking a long time to load - it's going through all the entities and removing their spawn eggs. It may take anywhere from 8 minutes to 20 minutes to load, so be aware.