Activity streams not updating.

When I add a new lesson, it has stopped updating the activity stream on both the group activity stream and the main activity stream. When I add a new topic and update the course, it just continues to load and states the following:

BuddyPress for Learndash enrolling users to the course buddypress groups. This can take a while if you have many students(members). Do not navigate away from this page until this is done.

The above never completes and just has a loading icon that never ends.