If you have crashed from installing two addons that conflict, or for some reason your game crashes after adding an addon, you can manually delete it from the files without starting the game.

1. Fully close the launcher and any Minecraft windows.
2. Go to your .minecraft folder (%appdata% on windows)
3. Then go to /libraries/me/deftware/emc-f-v2/latest-(mc version).
4. Delete the affected addon. If you're not sure which, you can remove them all.
5. Start the launcher and game.