You shouldn't really have to select the maptype. Just put the script in the correct folder, reboot the game if you have the script cached (just to be safe), load the map in the editor (heanry's map requires the TM2 title) and the script should automatically activate and show the available blocks at the bottom.
Try to re-download the map too. If you saved the map without the Puzzle script being active, chances are important metadata gets lost, fully corrupting your map (which mx will reject too).