I successfully (I think) managed to update my Helix LT few days ago. I didn't go to 2.80 but waited to go straight to 2.81 from 2.71. It all went smoothly, I now have a working Helix with 2.81.0 firmware, and my PC has HX Edit 2.81 installed along with Line 6 Updater 1.18.
After the update I didn't actually do anything with HX Edit so I don't know if it was working at that time, but now it is not.
In between my PC has updated Windows 10 which may be the issue! Neither HX Edit nor Line 6 Updater are seeing the Helix, just saying 'no device connected'. I have gone into Windows settings and looked at devices and the Helix is there, but it says 'Driver is unavailable' I have downloaded and installed the most recent USB driver, v1.91 but this hasn't changed anything. I have also tried different USB cables and also removed the Helix from Windows and reinstalled. It made hopeful noises, and gave messages telling me it was installed, but still the Driver unavailable message persists.
I'm stumped, any help would be very much appreciated.