Foamfix seems to cause a random Java Crash. It only happens about 50% of the time on game load up. Here's a Pastebin to the error: https://pastebin.com/X1zvP4QE
Line 94 is the one you'll want to look at.

So after 3 days of troubleshooting, I've come to this conclusion. The error is caused by three mods: Foamfix, TConstruct, and a mod that has a soft dependency on Construct. considering there are a lot of mods I'm using that has a soft dependency on TConstruct I will probably never figure out what the third mod is. I'm posting this update just in case it helps resolve the issue in any way. I know this because loading my mod pack without TConstruct fixes the issue but loading TConstruct and Foamfix alone together (with their required dependencies of course) causes no issues.

(By soft dependency I mean a mod that doesn't require TConstruct but recommends it because it adds in extra features)
Edit: More Info

I'm getting a similar issue https://pastebin.com/Q9051wAG

Try manually changing your Java version to a way more recent version if you're still launching the game with the default version. (Which is probably 1.8.0_51, the most recent version is actually 1.8.0_252 or something)

I started not getting random Java crashes when I did that.

We need a group issue for this. If anyone can figure out what's wrong...

For now, the best workaround I can think of is disabling the deduplicator - this is causing the on-load crash.