When choosing the number of categories for your puzzle, remember that it will be one more than the maximum number of blocks across or down in the grid, because the first two categories go to the left of and above the top left block, respectively, and are not repeated as the rest are. The first category is often easy to forget, since it is often an ordering, usually chronological. Keep that in mind and double-check that you haven't forgotten a category before entering that number into the form below; also, remember to include the entries in that category when filling out the form on the page that appears after you submit this one.
Please be patient while the causes of multiple errors and broken logic are corrected.