Tried to install MystWorld (1.5.0) to use with Roots 3 (3.0.21) and it crashes on the startup of the Enigmatica 2 modpack, the problem is not ocasionated by Roots 3, I removed R3 from the mod folder and it crashes without him, I am using MystLib (1.4.0)

could you post a crashlog?

See the Root issue for my comment there. You'll need to make sure that you also update Forge to 2847, if it isn't already. That seems to be the most logical cause at this stage.

Duplicate of MysticMods/Roots#358