When I startup minecraft, on the main menu it should say: Minecraft 15w05b. It says 15w05b/snapshot. This is unusual. Usually It says Minecraft 15w05b. I wonder why, if you cant find try finding your way how you are printing out the text message, and change it. I dont know if this is correct, but this is probably your code.

(Insert Class Here).print(Places.menu, LineNumbers.last, Colors.WHITE, "Minecraft 15w05b/snapshot");

Anyways, screenshot below.