RealVNC Viewer fails to connect to the MAS

Symptom

"Out of the box", RealVNC Viewer version 4.x.x won't establish a connection with the MAS. After entering the MAS IP address and clicking OK, RealVNC Viewer either never connects with the MAS, or takes many minutes to do so. Either way, no error messages are displayed.

Resolution

Start the RealVNC Viewer:

In the Connection Details dialog box, click the "Options..." button:

In the Options dialog box, select the "Misc" tab:

Check the option that says "Only use protocol version 3.3". Then select the "Load / Save" tab:

Click "Defaults - Save", then "OK" to close the Options dialog.

RealVNC viewer should now connect properly with the MAS.