Instructions for including gamestages and bookshelf dependencies have not been updated to reflect the new format in which it should be used. For example, in later versions of Minecraft, the following line:

compile "net.darkhax.gamestages:GameStages-MCVERSION:PUT_FILE_VERSION_HERE"

should instead be:

compile fg.deobf("net.darkhax.gamestages:GameStages-MCVERSION:PUT_FILE_VERSION_HERE")

otherwise the development environment crashes on run due to obfuscated mappings.

Thanks, fixed in 98c1cc3