Steps to reproduce:

1. Create some groups in a course.
2. Add a student to one of the groups.
3. Create a forum and set the group mode to "visible groups".
4. Log in as the student anc go to the forum.
5. Select "All participants".
6. A notification is displayed with the message "You are not able to create a discussion because you are not a member of any group. ".

• • Expected message: 'You do not have permission to add a new discussion topic for all participants.'