TypeError: a.key is null

[filipegarrett]

I don't know if this is still supported (seems unlikely that I'll get some help), but I'll ask anyways.

I have a large AngularJS project which implements ngStorage and, lately, we are getting a warning stating "TypeError: a.key is null". It has been a bit hard to go through whole project in order to detect where is it coming from.

So guidance as to what causes this and what could be done to fix it would be greatly appreciated =)