When spawning in a Vanilla world, none of the added ores actually generate. The rest of the mod works without problems.

Do you have any other mods installed? Like Quark?

I've got Biomes O' Plenty installed, but the ores don't spawn, no matter if it's Biomes O' Plenty world or Vanilla.

Ok, apparently it works without Biomes O' Plenty.

I can confirm that none of the underground generation like the different stones (limestone e.d.) and ores are generating.
I am running a bigger modpack of which Biomes O' Plenty is one of them.
Sadly i figured this out AFTER making a base in multiplayer...

This also does happen with to Quark, not just BOP. Maybe both are doing something that messes with stone gen

I'm having the same issue in my worlds, none of the mod worldgen is working, only other mods i have are journeymap and jei rest of mod working perfectly

the config looks like everything's enabled, haven't edited it at all

I am doing some testing and i am not sure which mods are causing the worldgen to malfunction now.
Playing only with Create does have worldgen in the worlds, but i added some of my non-worldgen mods and i couldn't find anything strange enough.
Will edit with more findings if i got any.

I'm having the same issues. I've confirmed that quark, for one, stops the ores from generating but in my new tweaked pack without quark, the ores are again not generating (using default mod configs).

There seems to be something incredibly inconsistent going on. I have Quark and Create working together perfectly fine, but also had issues with terrain gen in other worlds.

I can confirm that, i thought i somehow narrowed it down to just JEI, but when starting a world with Create and JEI alone, it still worked.

I guess I'll start going through my mods one by one. For everyone else testing this, you can use the Advanced Xray mod to quickly check if the ores are spawning. Keep in mind that by default the ores only spawn above y = 40 for copper and y = 55 for zinc.

I put all my mods back and created a new world and it works again. There is no rhyme or reason i can put to this.
It seems to just differ between worlds, maybe something seed-based somehow?

@Lordician I can test that. What's the seed of the world that worked?

I just created a world with the very same modpack, with the same seed as i use on my server.
Right below spawn there is a patch of Create stone, but when i check in the server, it is just normal stone.
Also, the server just started to generate chunks with the stone, but all the other chunks i checked that had already been generated (there has been a server restart) were barren of any Create materials.
EDIT:
After recreating the world many times in singleplayer, i decided to restart my game and do it again.
Which resulted in the same chunk, where a patch of Create stone was, without the very same stone.
In fact, i can't find any of the stones nor ores around.
Though it seems Simibubi has pushed a fix already, i hope that solves the issue.

Just compiled that new commit, and the issue seems to be fixed. Thank you!

Thanks for the confirmation, 0.1.2 is uploading.