I checked Level 14 and 14New from the Erim collection in the Sokoban Puzzle Solver 3.7.2. This program indicates that neither puzzle can be solved.
Is this correct? Is there another solver program that someone can recommend that might be a better one to use?
Is is easy to delete levels from a collection that cannot be solved, so that the entire remaining collection's ball can turn to yellow when the good levels are solved?
Any help would be most appreciated.