Thanks for sharing this error report. It's pretty clear that the IP Address is valid and I was also able to trace it successfully on the same version of PingPlotter that you are running. This could be a result of adapter configuration or routing on your machine. An easy way to test this would be to disable all but one adapter and run the trace again. Using a VPN connection could be the issue so I would be interested to know if that is the case. If you are able to disable a network adapter and resolve the error then you might take a look at the priority of the network adapters to drive traffic to the one that is best suited to test the IP address.

P.S. You could also download and try the same IP address using the new PingPlotter version 5.