Rails - Acts as Nested - Impossible move, target node cannot be inside moved tree.

Hello, I’m using the Awesome Nested Set plugin: https://github.com/collectiveidea/awesome_nested_set

And in my model I do the following:


after_save :ensure_max_nestedset_level


def ensure_max_nestedset_level

if self.level > 2




I do this to keep the levels from getting to deep. Any idea why I’m getting this “Impossible move, target node cannot be inside moved tree.” error? What’s strange is it happens on production but I can’t replicate it on Dev.


Had the same very strange bug too

I suggest that you put some logging in immediately before the move and
log details of self, parent and parent.parent and see what is shown
when it crashes. My guess is that the tree is messed up in some way
and you have ended up with something like self being its own

Another suggestion is to look at the code of Awsome Nested Set and see
what is the condition that generates this error.