Hi! When I did follow instruction from https://www.howtoforge.com/tutorial/how-to-upgrade-debian-wheezy-to-jessie-stable-release/ and now I can't get into ISPConfig and another websites shows "Forbidden - You don't have permission to access / on this server." What else I can do to get server to work again?
Login to ispconfig, go to tools > resync, select sites and resync all websites. This will update the website syntax for all sites from apache 2.2 to 2.4 syntax.