I had a problem with mongodb table. In my case primary key had string type and FormBuilder::build failed with error because "$items->where($primaryKey, $this->getIdentifier());" did not return nothing. So, I propose to add to user model castIdentifier method if you need to cast your identifier to non-integer value.
I had a problem with mongodb table. In my case primary key had string type and FormBuilder::build failed with error because "$items->where($primaryKey, $this->getIdentifier());" did not return nothing. So, I propose to add to user model castIdentifier method if you need to cast your identifier to non-integer value.