When trying to connect to a RealVNC Server you may see the following error:

Why does this happen?

By default, RealVNC Server only allows connections from users who are members of the Administrators group on the remote computer.

How do I resolve this?

To allow other users and groups to connect you will need to add the user or group to the RealVNC Server's Users & Permissions.

You can either add a group of pre-registered users or individual accounts. Users can be registered from both local and domain accounts and groups.

When running RealVNC Server on Windows, users and groups can be selected using the Object Picker UI: 

Once the user has been added, permissions can be set for that user/group and users should now be able to authenticate successfully.

For more information on permissions, please see Managing Users and Session Permissions for RealVNC Server