Mod version 3.0.6-b227
Forge version 14.23.1.2601
also encountered the same issue with 3.0.6-b228

When generating a new world the game crashes at the dirt screen.
Logs mention about an invalid block ID in an existing schematic.

latest.log

@ScytheIronclaw
FYI, we prefer you use pastebin.com or gist over linking to an uploaded file. :)
Also, it would be nice to have the crash report or the fml-server-latest.log instead of the latest.log. In 99% of all cases, those are the ones that'd contain the useful information.

"This crash report has been saved to: C:\Users\<your user-name>\Documents\Curse\Minecraft\Instances\Custom 1.12\crash-reports\crash-2018-01-27_16.05.22-server.txt"

latest.log is enough in this case, I already fixed it (simple one line fix), but I have to finish what I was working on before before I can push.