The Scramble and Missing badges are like puzzles -- sometimes every block has to be in right order before it'll unlock. Sometimes you have to switch similar-type blocks around before the software registers it as 'complete' and the mod will run in the simulator. For example, in one of the puzzles, the correct answer is Two Mississippi!! One Mississippi! Three Mississippi!!! Exactly in that order. The correct answer is in deliberately counterintuitive order, because we want students to rely on running the mystery mod mod first, not guess what the correct answer will be.
If you ever get stuck, make sure you've followed this strategy: First, run the mystery mod in Minecraft to see what it does. (the mystery mod buttons are located under the badge's title) Be sure to pay attention to everything from the text area to block types. Then, try to reproduce the code. Click for hints, if you need to. When you reach 100% complete, run the mod in the simulator and the badge will unlock.
If there's any text in the mod, the text will appear in the lower left corner or bottom of the screen when you run the mod. The font size may be small. In minecraft, any text will appear in the chat area where you run commands.
(Here's how hints work: If a block is placed in the wrong location, or you inputted a wrong number, variable or material type, a block will flash until you've corrected the problem. Blocks will flash one at time.)
With scramble badges, be sure to check for blocks buried under other blocks and scroll to the very edge of the page for far-flung blocks.
If you find that your badge is still unlocked, there could be a bug. Please let us know by submitting feedback about the particulars of the problem, being sure to attach a screenshot.