After the user authenticates and is connected to a server-side APPX session, WinAppxD has nothing further to do with that client/server session. If WinAppxD is killed, ends with an error, or experiences a hung port, this will not affect users who have already established APPX client/server connections. (A problem with WinAppxD is the most common cause of the error situation in which no new users can login, but users who are already logged in, can continue to work.)