500 Error when adding an SSH key (5.1)

[tste...@unl.edu]

When trying to add an SSH key, GitLab is bailing out when it tries to send the user an email.  This is happening in version 5.1.  Any help would be appreciated.

Here's the relavant information from production.log:

Started POST "/keys" for  at 2013-04-24 11:28:48 -0500

Processing by KeysController#create as HTML

  Parameters: {"utf8"=>"✓", "authenticity_token"=>"********", "key"=>{"title"=>"Foo", "key"=>"ssh-rsa ******** foo@bar"}}

Completed 500 Internal Server Error in 56ms

TypeError (can't dump anonymous class Class):

  app/services/notification_service.rb:16:in `new_key'

  app/observers/key_observer.rb:9:in `after_save'

  app/controllers/keys_controller.rb:21:in `create'