What do about puzzle caches that are no longer solvable?

Hey, just had a quick question for everyone. There are a few caches around here that require solving a Flash puzzle in order to get the coordinates of the cache location. As you may know, Flash hasn't been a thing for awhile which makes the puzzle unsolvable. Unfortunately, the cache owner passed away in 2019 so I know that it won't be resolved. Should I mark it as needs maintenance or needs archived or just leave a note? Thanks?