If you have been unable to boot your Zorin OS 16 Installation USB Drive due to an "EFI" error, please download a new copy of Zorin OS 16 Core from the Download page.
If you purchased Zorin OS 16 Pro, please re-download your copy using the link in the email you received after the purchase, or request a new one here:
Request new download link for Zorin OS Pro
We recently identified an issue that prevents a small number of computer models from booting Zorin OS 16 Installation USB Drives. The issue was caused by a regression in the upstream shim package (see Launchpad bug for more details: https://bugs.launchpad.net/ubuntu/+source/shim/+bug/1937115).
We have now fixed this issue in Zorin OS and have uploaded updated .iso files for Zorin OS 16 Core and Pro.