I cannot enable Guest Account. Logged as admin, I got at Users & Groups, select Guest User,and tick Allow guests to log on this computer. Even when ticked, "disabled" appears bellow Guest User account label. When I switch to the admin account and then back at guest account (within preferences) the box is now unchecked. Any ideas what can cause this?
p.s: I don't have FileVault
So I thought to try a restart. A guest account is has appeared and working (looked disabled before restart) but I cannot open Users & Group Prefs. When I select it I get: Could not load Users & Groups Preference Pane.