The ISY and its PLM can communicate with the EZIO8SA through its PLM.
The ISY PLM was removed from the ISY and connected to the PC. Either the Utility cannot connect to what was the ISY PLM or cannot talk to the EZIO8SA through its PLM. If the Utility cannot connect to the ISY PLM which is known to be working, the problem is on the PC side. If the Utility can connect to the ISY PLM but cannot connect talk to the EZIO8SA through its PLM which has been confirmed to be working since the ISY can communicate with, I have no idea. The PLMs have been confirmed working at their current plug points, the EZIO8SA has been confirmed working. If the Utility can connect to the PLM, Serial communication between the Utility and the PLM is working to have obtained the PLM information displayed at the bottom left side of the Utility screen.
There is a check box on the Insteon Traffic tab, Trace PLC/PLM Raw. Check that box before entering EZIO8SA PLM address into EZIOxx tab. Select all the trace entries in the Received Insteon Traffic pane, use CTL C to copy to clipboard and paste to forum.