The notification e-mails contains a link. When you click on a link you get a error message:
You do not have permission to view this resource. Please contact the Site Administrator.

Even if you are logged in earlier.

Hi Ivo,

I created test user, and user softtest add test uset as friends. and I click link at email notification, no permission issue.
I missing something here?

After you are logged out, you get the permission message.

Is it possible you send the user to the login form, if the user is not logged in allready?

Hi Ivo,

this is the valid bug. but here the fixes.
1. edit /components/com_community/templates/default/guests.denied.php
2. changing

$this->load('frontpage.guests.php');

$this->load('frontpage.guests');