You can try to codify for example https://pixelogic.app/every-5x5-nonogram#10725003 as "11-31-1-12-0+11-3-1-11-11" (is there an standard in the community?) and add the 9 million "unsolvable" codified strings to a vector and sort the vector, and then look for not repeated consecutive. For example, your case "1-1-1-1-1+1-1-1-1-1" should appear exactly 120 consecutive times in the sorted 9 million vector. Is there one that is not repeated?
Feature request: It would be nice to have a jump to unsolved puzzle. In section 1 it's difficult to find an empty one. Also, there is something weird with scrolling.
Feature request: It would be nice to have a jump to unsolved puzzle. In section 1 it's difficult to find an empty one. Also, there is something weird with scrolling.