The following error message can be seen in the SureBackup log:
[timestamp] <01> Error A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond xxx.xxx.xxx.xxx:443 (System.Net.Sockets.SocketException)
Veeam Backup & Replication is not able to connect to the Virtual Lab and grab network settings from the web server.
If you assign a proxy appliance an IP address from the same network where the Veeam B&R server is located, Veeam B&R will automatically add a new route to the routing table on the Veeam Backup server, so please make sure that the 443 port is not blocked.
If you assign a proxy appliance an IP address from a network other than that where the Veeam B&R server is located, you will have to manually add a new route to the routing table on the router in the production network. Otherwise, you will not be able to access virtual machines in isolated networks.
Ensure that the specified network settings on the "Proxy" step of the Virtual Lab wizard corresponds to the production settings.