Cannot send email notifications on new comments. The PageCommentsNotification.ftl template script that is used to compose the mail body contains the expression:

${model.retrievePageLink(path)}

The model class PageCommentNotifModel fails when the retrievePageLink() method is invoked. See error log attached.

To reproduce:

1. Export the sendMailOnPageComments listener configuration.
2. Install Observation module (not installed by default although listeners are present. When installed, will wipe out listeners.)
3. Import the sendMailOnPageComments back in.
4. Enable the listener.
5. Configure mail.
6. Add a commenting component in /demo-project/about/history
7. Leave a comment on the page.