Everytime i create a new world, many blocks are missing.
If i try /mw create test normal DEFAULT :
It creates a world where several blocks are missing or not generated.
Blocks that are missing are mostly blocks from other mods, but also granite, diorite and andesite.

I use forgeessentials-1.12.2-12.3.60-server.jar
On MC 1.12.2 with forge-1.12.2-14.23.5.2838-universal.jar

I have tested and figured that having Quark mod installed causes this issue. Quark has some world gen settings for creating ravines and underground biomes. It also alters the gen for diorite, andesite and granite. Perhaps FEMW doesn't allow that quark does his thing or Quark interferes with FEMW. Perhaps both authors should look into this. It's not an Urgent problem, but a fix will be nice. I might post this at Quark repo too.