If I click on the “Installation Guide” link from https://igniterealtime.org/projects/openfire/documentation.jsp then it takes me to http://download.igniterealtime.org/openfire/docs/latest/documentation/install-guide.html and it displays “Forbidden”.
Something needs help.
Meanwhile you can access it here https://htmlpreview.github.io/?https://github.com/igniterealtime/Openfire/blob/master/documentation/install-guide.html
Sorry about that. There was a puzzling permissions setting on the uploaded documentation files with the last release. I have fixed it now I believe. Thanks for reporting it.