Reinstall Blockland.
Download the Mac OSX.zip file from http://blockland.us/files/Blockland_16mac.dmg, which contains all of the game files, including UIs.
No,
why the mac file?
Night Fox is using Mac and thinks everyone on the forum owns one, obviously.
No, because the Mac file contains all of the pictures and bin crap, whilst the windows download would give you an installer(of course you don't want to re-install blockland)