Mod Versions:
backportedflora-1.5
Novam+Terram+1.12.2+-+7.3
Forgelin-1.8.4
Quark-r1.6-179
AutoRegLib-1.3-32
Forge-14.23.5.2847

Crash description:
when exploring a world with said mods installed the game crashes during world gen
to reproduce use seed 4586514347051193556 and teleport to x=-799.61, y=80.86, z=399.10

Crash Log:
https://gist.github.com/spyguy26/0f2ed45c8bc44eec0e5e227f16546b7f

Got the same error

Nothing to do with Novam Terram though, don't have that mod.

https://gist.github.com/mmmilord/5b6139957473a555aa5eb69065e422a7

same error and crashlog, however i had vanillafix installed and it told me the mods being suspect were backported flora, and quark. i dont have novam terram, so i agree with @mmmilord in that its not related to novam terram. here's my crash report.

Judging by the logs it's caused by Quark simulating the use of bonemeal to generate its lush caves.
Shouldn't be too difficult to fix, I'll look into it

Seems to be fixed now.