I have almost the same problem, I've already install Zorin OS 16 Beta and tried to upgrade a clean installation as recommended but without any success.
Can you boot into Zorin but hold the Left Shfit key starting at boot to bring up the Recovery Menu.
From the recovery menu, arrow key down to "Enable Networking."
Once that is done, bump back up to the Recovery menu and arrow key down to "Drop to Prompt". Hit
sudo add-apt-repository -y ppa:yannubuntu/boot-repair
sudo apt install -y boot-repair
Once the process is completed, test by rebooting.
2 posts were split to a new topic: Zorin OS 16 Core install Fail EFI boot - invalid parameter
A post was split to a new topic: Zorin OS 16 Core install Failed to open EFI boot
Some instructions for how to fix this, I dropped in another post as I was experiencing the same issue. I know that @Aravisian has also posted the same solution
I had a similar problem with my Dell Latitude too.
To circumvent this issue whilst awaiting the shim update for the ISO, in BIOS you should be able to select a new Boot option. From here, plug in your USB with the ISO, browse to the EFI\Boot\ folder then select grubx64.efi file and name this Zorin or something similar.
Exit BIOS and restart, then hit F12 (I think?) and chose 'Zorin' as your boot option and it should, fingers crossed, load to the Live Installation option.
Let me know how you get on.