There seems to be an issue with the mod:

• https://paste.dimdev.org/emevicineh.mccrash

• https://paste.ee/p/BZRtg

I'm getting the same error, usually with the same stack trace, though sometimes it's a bit different:
https://paste.dimdev.org/ecafidalaw.mccrash
https://paste.dimdev.org/ucemicenig.mccrash

I can consistently replicate this crash by loading certain chunks in my world. It also only started happening when I updated a bunch of other mods, so BetterFoliage is unlikely the root cause here (unless it's a Forge incompatibility); thankfully my modlist is quite different from the original reporter, so I should be able to track down the real culprit if so.

I've figured it out- this is an incompatibility with newer versions of forge. Downgrading my forge version from 2834 to 2816 fixed the crash. I will continue narrowing it down to see if I can pinpoint the exact forge version that is incompatible with BetterFoliage.

I have narrowed it down: this crash is caused by Forge versions 2832 and above.
Downgrading Forge to 2831 or below fixes the issue.

@RodrigoTaipe93 - could you please update the title of this bug report to make it clear that this is an incompatibility with Forge versions 2832+

@octarine-noise the effect of this issue on my particular set of mods means that we are currently unable to update Quark past version r1.5-151 (as it requires a newer version of forge), until BetterFoliage updates their Forge dependency

(Please let me know if you need config files / world data or anything to help replicate the issue.)