The Red Checkbox means that you have auto-ping feature enabled in connection properties and either the remote PC is unreachable or it's an Internet-ID connection (and auto-ping works for direct connections only).
How do I get rid of the red checkbox by a remote PC.
Please check if the auto-ping function is enabled: 1) Right-click on the Remote Host and select Properties 2) In the connection properties window, go to the Auto-ping section and deselect the checkbox:
You can learn more about the auto-ping feature here.
We would also recommend you to update your Viewer to the current version 18.104.22.168. It's available for downloading here.