Subscription Manager - How to alert Subscription to Visitor

[trungnt]

I have a forum, which have premium content

I want users to see the message that they need to subscribe so that they can access this forum.

I have setup the subscription manager already, but users cannot see and realise that they need to subscribe

What they see is like this

You are not logged in or you do not have permission to access this page. This could be due to one of several reasons:

1. You are not logged in. Fill in the form at the bottom of this page and try again.
2. You may not have sufficient privileges to access this page. Are you trying to edit someone else's post, access administrative features or some other privileged system?
3. If you are trying to post, the administrator may have disabled your account, or it may be awaiting activation