Error 22 and 503 on new installation

I migrated a site to a different server. Everything works (after I changed server php from 4 to 5, except now I get this at the top of the pages.”Warning: HTTP Error:22/The requested URL returned error: 503 at https://www.mkgarden.org/wp-content/plugins/zingiri-forum/mybb/member.php?zing_url=http%3A%2F%2Fwww.mkgarden.org%2Fwp-content%2Fplugins%2Fzingiri-forum%2Fmybb&zing_wpdb=mkgarden_newsite&zing_wpf=wp_zing_mybb_&zing_wph=localhost&zing_wpu=mkgarden_ted&zing_wpp=Geneva118%21&zing_wpblogloaddir=%2Fhome%2Fmkgarden%2Fpublic_html%2Fwp-content%2Fuploads%2F&zing_prefix= in /home/mkgarden/public_html/wp-content/plugins/zingiri-forum/includes/http.class.php on line 179″.

I’m a newby and don’t know what to do.