Why do users with permission to post commenst get "You do not have permission to post a comment"? I have some users with roles administrator, authenticated etc. All such user roles have permission to post a comment.

But when posting a comment it is showing error "You do not have permission to post a comment." along with "Your comment has been queued for review by site administrators and will be published after approval."

How can I solve this issue?
Go to the admin/people/permission check for comment section in permission page where you can see skip comment approval you need to give appropriate permission for the user. 

Like below screenshot.