Softlock / Freeze in a drop down menu

duplicape derp

Every time I use a drop down menu, like the world type, game mode and some command block options, the game freezes. I don't know if this is a clone or not, but I don't know any clones. This is a big problem because one of the command block's features is its three states. I can currently get away with the world settings (/gamemode c or /gamemode s for gamemode, /difficulty p/e/n/h for the difficulty, and download a flat world for the flat setting)

And if this is a clone, please kindly lock it and redirect me to the original issue. I still think this is a clone. I might have lots to add there. (Note that this also affected previous version 1.0.4, but I can't add it)