When I try to install the Varia firmware update 3.70 using Garmin express the installation hangs when it tries to load the license. ciq.forums.garmin.com/.../1274142.png
Same thing on my Mac running High Sierra, but if I was quick enough clicking on Accept it got to the next step, then immediately crashed Garmin Express. I tried this a number of times, including rebooting and changing to my admin user account. I finally looked in the Garmin folder on the unit and the update file was there! When I started it the lights blinked to show that it was installing, and it now shows 3.80 in Garmin Express.
I have the same issue when i tried to update my Edge 820 using Garmin Express. Garmin Express would freeze and eventually taking a lot of system resources. Eventually i had to kill the process. This happened repeatedly so i stopped trying.
I encountered the same thing (license agreement hang & app crashing)... it took me ea few tries, but I was able to get the firmware updated.
Interestingly, the about box on the app indicates there is a new version available ... but clicking on the link in the box doesn't do anything. Downloading Garmin Express Mac from the website installs the same version (3.70).