Area navigation settings not responding

the problem I have, is that one of my site's area navigation settings page doesn't respond instantly after entering it (I can't do any action). I saw few people with similar problem, but for them, at least, the problem was appearing only with while working with few particular nodes. So what I want to ask, what could be the causes and is there a way to fix this issue without redoing all the nodes? Or how could I diagnose the problem, because ULS didn't helped me at all.