I had a client (Windows) which has switched the network from public to private. The firewall exception for UrBackup was only set for the public network. So the backup did not work and I needed some time to figure out whats wrong.
I increase the robustness of UrBackup, I would suggest that the client checks the firewall settings automatically, either periodically or when the backup fails. Then there could be a message that the settings are not correct and if they should be corrected.
Backup is a curcial function, which most people don’t really look after, so I think everything which makes the process more robust is a big advantage.