How do you mark threads as read using the web browser.

[reefwiser]

I can mark all new threads as read?
When reading the unread messages it tapatalk it is easy to tap on the check to mark the threads as read.
But on the computer web browser view where do I go to mark forums as read? Wehn I click on forum actions> Mark Forums Read I get an error message that no forum is selected and contact an administrator.