Hi, the changes in commit 3ea74eddb make this fail

  def changed_exposed_fields
    self.changes.keys
        .each_with_object({}){|key, hash|
                              hash[key] = self.changes[key][1] if
                              self.class::EXPOSED_FIELDS.include?(key.to_sym) }
  end

with

Exception encountered: #<NoMethodError: You have a nil object when you didn't expect it!
You might have expected an instance of Array.
The error occurred while evaluating nil.[]>

in the line with self.changes[key][1].
From reading the commit diff I can't really tell why. Do you have a clue?

--Frank