OceanFloor-1.12-1.0.1
forge-1.12.2-14.23.3.2673-installer-win

It seems fine when I leave the config as is, but I don't just want a few small patches of clay and sand, but want a lot of sand in the oceans. So I changed the config to:

I:clay_chance=65
I:clay_size=32
I:dirt_chance=30
I:dirt_size=18
I:sand_chance=85
I:sand_size=200

And it's crashing:
crash-2018-05-10_11.41.12-server.txt

Revisiting this and it's still crashing if I push the numbers too high.
I:sand_chance=128
I:sand_size=128

crash-2019-02-28_17.56.44-server.txt

Hey sorry i never checked this issue tracker ill be more frequent. i never fixed it since because theres no one number that is a hard limit, just if its "too big" then some chunks sometimes overflow.

If size 32 crashes for some people then it wont crash for others so i kinda got stuck and walked away. 1.14 will be a whole new world though