A connection to the remote computer failed to open the RPC (remote procedure call) port.
There can be a number of causes including firewall issues, name resolution problems, network hardware problems, or the target computer rebooting during a connection. This can also be caused by a problem with the spooler service (e.g. disabling the Print Spooler Service will cause this to eventually occur in reports in PDQ Deploy and Auto Reports in PDQ Inventory).
Verify that the target computer can be connected through SMB to its ADMIN$ share. Check related services such as the Spooler Service and ensure they are running. The PDQ service(s) may need to be restarted if the spooler service was not running previously. If the issue persists contact support for further assistance.