Continuing the discussion from Make private group pages visible to only group members:
Steps to reproduce:
Create a group and uncheck “Group is visible to all users”
Add non-admin members to the group.
Each member will see the group as a link on their own profile (but not on others), but using the link will give an “access denied” error.
Either the link should not be visible to the member, or the member should have access to the group page.