I have installed ispconfig 3 with apache on my ubuntu system. Recently I installed varnish which is configured on port 80. Apache2 on port 8080. Also Nginx is used for SSL termination/Proxy pass which is listening on port 443. Whenever I request a URL example.com I gett the 403 forbidden error. But when I stop Nginx and varnish, the site runs without any error. I also have installed lets encrypt for https. Can anyone help me with the problem ?