Have many insteon switches with ISY994. Integration worked fine for while. Had updated core no issues but following AM with very brief power outage (seconds) and everything messed up - keep getting message - “Retrying setup: Invalid XML response from ISY; Ensure the ISY is running the latest firmware: ISY Could not parse response, poorly formatted XML” deleted integration and restarted to no avail. I can easily log on to my ISY device with no issue and seems functioning well, just the integration not working - HELP!!!
Did you ever find a solution to this? I’m having the same issue (except that I haven’t ever been able to get it to connect).
Nope when insteon had their issues abandoned technology and swapped out to zwave/zigbee