Drupal Commons notifications queue is not working I have a site where we noticed the notifications are no longer working. The Queue states there are 238 notifications, and they are set to process immediately. The send method is "mail," and other emails go out from the site with no issue (e.g. registration emails).

I'm looking for any information which may help me troubleshoot this issue. There are no entries made in the watchdog table, no settings that I can see to log any kind of debug information, and no general setting or indication where I can see that would cause the problem.

The only thing I can guess is that updating Drupal Commons from an early version to 1.5 broke notifications in some way that I'm not familiar with.  The only significant thing I turned up on Google is this: http://network.acquia.com/node/1469103.

It's a combination of so many modules interacting that I'm honestly not even sure where to start.
The most obvious thing would be that cron is not running. You can see the last time it ran by looking at the site status report, that will also give you a link to run it manually.