How to reproduce

1. Copy any jenkins.war version listed in "Environment" on a machine similar with the ones described there
2. Configure JENKINS_HOME to use a new, empty directory
3. Run Jenkins with "java -jar jenkins.war"
4. Install email-ext v2.3 and promoted-builds v2.14.1
5. Create a new job and add a new promotion process
6. Add a new action of type "Editable Email Notification". PROBLEM: When the action is selected from the "Add Action" drop-down, its UI doesn't appear. It's as if the selection wasn't made.

Notes

• Firebug shows an AJAX call going out to the server and the response contains a lot of the expected HTML/JS; however, nothing is actually displayed in the browser
• The server's console log doesn't show any messages, error or otherwise, when step 6 is attempted
• email-ext works as expected when it's configured in the "Post-build Actions" section of a job's configuration page
• Tested the two plugins with a couple of Jenkins versions going back to v1.400. Fortunately, I found that the problem manifests itself only going back to v1.403. On v1.400 and v1.401 the problem doesn't appear; v1.402 doesn't exist. Also of importance, I configured a job with this type of action on v1.401 and then loaded the configuration on v1.418 and email-ext's configuration ui appears on the job configuration page. I still can't add new email-ext actions for promoted-builds from the ui, but it seems that they work if I add them manually, by editing the job's config.xml.