This error was resolved by some by opening it as admin - in Zorin OS, this would mean launching with sudo.
But I wouldn't.
And I would avoid Balena Etcher. This is a bug in Balena Etcher and even if running as admin seems to work; using a bugged Etcher is a bad idea.
I know you have put a lot of work into trying to use Balena Etcher. But I believe you are better off cutting your losses and not wasting more time with it.
We can try another Etcher... OR, you can use Gnome Disks which is already presently installed on Zorin OS.
To use Gnome Disks:
- Insert the USB Drive
Plug in the USB stick (ensure it has 32GB of free space. If you do not have a 32gig stick, at least greater than 8 gigs. But bigger if you have it for safety margin).
- Open GNOME Disks
Click on the Zorin Menu (App Menu). Search for Disks and open it. In the Disks GUI window, select the USB drive:
- Select the USB Drive
On the left side (left pane), find the USB stick listed (do not select the internal hard drive).
- Format the USB Drive
Click the three-dot hamburger menu (⋮) in the top-right corner.
Select Format Disk
Choose Quick Format and set the partition type to GPT.
Click Format.
Once that has completed:
Click the three-dot hamburger menu (⋮) again.
Select Restore Disk Image
Click Browse and select the Zorin OS ISO file.
Confirm that the correct USB drive is selected.
Click Start Restoring and enter the password if prompted.
This will burn the Zorin OS .iso file to the USB stick.