Cannot read property 'apply' of undefined

[ansaries]

Hi,
I am getting the following message when using requireValidUser in resolve:

Cannot read property 'apply' of undefined
at Object._this2.(anonymous function) [as requireValidUser].

I tried reading the src, i think the error is somewhere on line 199-200. I couldn't understand the code logic that what rootScope is doing there :)

p.s: please ignore my basic knowledge.
regards,
Arslan.