Bob, do we know as yet whether the DCOM Authentication needs to be changed back again. I had to manually install the update yesterday but haven't had a chance to test things. I am still only having trouble with the TCS.exe telescope program which doesn't connect via USB ( although I can send it commands through the serial monitor still) . I have sent the hardware away for testing but hadn't thought the issue was related to this as there wasn't anything in DCOM related to TCS.exe, only things were the ASCOM simulators, ACP and SkyX