I have a project which was running very well before upgrading to latest mongoid. I have relationship that looks something like:

User
has_many :authentications

Authentication
belongs_to :user

When creating new record of both User and Authentication everything seems to be running well but when updating existing User object, error above appears. Update code looks something like:

user = authentication.user
user.first_name = first_name
user.last_name = last_name
user.nick_name = nick_name
user.save

Application throws exception when you call user.save

Hope somebody clears out a solution or at least somewhere where I can start looking.

Thanks