In Xcode 10, I'm having this issue where previously working extensions (from the store and some of mine), that have been working fine for a long time, are suddenly disappearing from the Editor menu and System Prefs - > Extensions.Restarting Xcode doesn't help.Restarting Mojave doesn't help.The only thing that helps is downloading a fresh install of Xcode (clearly an unworkable solution).Is anybody else experiencing this or has managed to resolve it?