We have the problem that AFTER a disconnect of a remote session we get the message:
"Failed to connect to server (DNShostName~50)" - actually in German it reads "Fehler beim Herstellen einer Verbindung mit dem Server (DNShostName~50)"

The initial remote session works, only if it breaks a reconnect is only possible after a reboot of the remote host. In addition the client does not lock the screen if the connection is lost.

I noticed that the listening IP stack does not listen any longer. Before the problem, when doing a "netstat -a -b" I can see 2 entries for nzrWinVNC.exe:
Proto Lokale Adresse Remoteadresse Status
TCP [::]:5950 LWS71127:0 ABHREN

But both listening ports are gone after I have lost the remote session.

We have ZCM 10.3.3 on Win7 64bit with an internal CA and MS-SQL DB. Problem exists at least since 10.3.0

Most important policy settings:

Remote Control Settings
x Allow managed device to be controlled remotely
x Ask permission from user on managed device before starting Remote Control
x Give visible signal to the user on the managed device during Remote Control
_ Give audible beep to the user on the managed device every seconds during Remote Control
x Allow managed device screen to be blanked during Remote Control
x Allow managed device mouse and keyboard to be locked during Remote Control
x Allow screen saver to be automatically unlocked during Remote Control
x Automatically terminate Remote Control session after inactivity of "30" minutes

Password Authentication
x Enable password based authentication
Minimum password length "7"
Password type
_ Session
x Persistent
x Allow user to override default passwords on managed device
Default ZENworks password:
_ Clear password (if any)
x Set password
Default VNC password:
_ Clear password (if any)
x Set password (password should not exceed 8 characters)
Intruder Detection
x Enable Intruder Detection
Suspend accepting connections after "5" successive invalid attempts
Automatically start accepting connections after "10" minutes
Session security
_ Enable Session Encryption
x Allow connection when Remote Management Console does not have SSL certificate
Allow up to "2" levels in Viewer certificate chain
Abnormal termination
x Upon abnormal termination of remote sessions, "Lock Device"