I just got a few lamplincs yesterday and I was going to link them with the ISY. I put the ISY into linking mode and then did the same with the first lamplinc. I registered the lamplinc and put it in the list. I clicked finish and it was doing it's normal thing. Part way through the process it returned a "Could not determine Insteon Engine" error. I thought that maybe I was having some comm issues at that location so I moved to a new location, closer to another insteon device and an AP. Same result. I kept moving around the house and on my 4th attempt, the ISY was not able to see the lamplinc at all. To be sure I went back to the original location where it could see it at least and it didn't this time around.
So I then decided to install a new switchlinc that I hadn't quite gotten around to yet. Yet again no results. My ISY is on the 4.0.5 firmware. I decided that maybe a power cycle of the ISY/PLM might be a good option. This seemed to make my problem worse. While I hadn't tried to control some other insteon device during the whole linking business, after the power cycle admin console was, what I surmise was, reestablishing comms with my insteon devices. After each "system busy" type progress bar it would return an error stating that it could not establish communication with insteon device. So I click okay and that cycle continues until all of my devices are confirmed to not have communication.
So I power cycled again. To no avail. I wanted to check the firmware version of the PLM so I went to check "PLM Status/info" and it returned the address and what looks like a revision number stated that it was connected. Funny thing though was that the PLM wasn't in fact connected. So bottom line trying to figure out where I go from here since it doesn't actually seem like I'm actually having a comm issue since everything else worked perfectly before I attempted the lamplinc situation.
Thanks