奇怪的错误阻止用户编辑设计配置文件

I have an application under development in Rails 3.2.13 with devise, omniauth and cancan. It all worked perfectly until I started to implement authorisation with cancan. It is even more interesting that cancan itself works like charm but generates an error in editing the user profile provided by devise. If cancan does that at all, I'm really not sure.I have an application under development in Rail