Installer stuck with: GetVar Variable Not found

[pefl]

I’m trying to install /e/OS on a Fairphone 6 with the Web Installer from Brave browser on Linux.

Fairphone buildnumber is: FP6.QREL.16.100.0

When the installer boots my phone to bootloader and asks me to connect again I get the following error: “Cannot read unlock state: Fastboot command failed: GetVar Variable Not found”. I also get the same error with Vivaldi and also when trying from Windows.

Phone looks like this when I get the error:

I found the Safe Guide to install when Web installer fails here. [HOWTO] a Safe Guide to install "IMG-e-builds" even if the /e/ web installer fails

I have updated fastboot to version 37.0.1-1573314 and have been able to do:
$ fastboot flashing get_unlock_ability
(bootloader) get_unlock_ability: 1

But other fastboot commands just makes the phone go into some kinda half-reboot-screen and the command prompt just says “< waiting for any device >“

Commands that don’t work:

$ fastboot oem device-info
$ fastboot flashing unlock

Since I can’t perform fastboot flashing unlock, I’m pretty much stuck here. And since everything feels very unstable I’m not sure if I want to try to proceed either.

[GabrielT]

It looks like driver issues.

Try downloading fastboot drivers for your device, perhaps on Fairphone website or Android website.

Alternatively, try installation from windows after having connected the phone at least once in fastboot for windows to detect the “fastboot device” that will then trigger an optional windows update driver download that is necessary for the rest of the installation to work

[pefl]

Updating drivers seem to have done the trick. Thank you!
I got my Windows environment up where different fastboot commands responds as expected. I didn’t manage to get my Linux machine working properly (the second fastboot command always forces reboot whetever the command is)
I will continue with the /e/OS installation from Windows when I feel I have the time required.