I've read through the other issues regarding the pack not launching and followed through their listed solutions, be it reinstalling the modpack, removing the ModularSystems folder, etc. The pack is still crashing after it hits step 5 out of 7 on the loading screen.

Here is the crash log.
https://gist.github.com/wsanders99/e637a61b4bfa00b87036cb8ed54f623d

Remove the ModularSystems configs or remove the mod.

I guess I'll just remove the mod. Removing the configs didn't work. I don't understand why it just stopped working since it was working for the past three days.

Oh, just got the same issue on our server. Looks like the version check of the mod is causing it and there is no option to turn that off, so the only way is to remove the mod.