system bootOrder not found

I found the solution on another forum. Two steps. Select a UEFI file as trusted and given it a custom name. Then go to the boot menu and select it as first priority as described below.

PROBLEM SOLVED! It turned out the problem was in the bios settings. I switched "secure boot" on which unlocked few more options. One of them was "Select an UEFI file as trusted for executing" that's in the "security" tab. After that it showed me HDD0, I hitted enter and "EFI" showed up. After another ENTER it showed 3 folders "ubuntu", "microsoft" and "boot". The ubuntu folder contained "shimx64.efi", "grubx64.efi" and "MokManager.efi" I'm not very familiar what all of them were, but I chosed "shimx64.efi" which was then added as "trusted for executing". I went back to the boot tab and found "EFI boot0: ubuntu" or something like it. That's because I named the "trusted" UEFI file "ubuntu". I moved it up to first priority and everything worked like a charm. Thanks for the advices, they made me search for my own mistakes in the bios configuration.

I want to add something to Melebius' answer for users with HP UEFI/BIOS:

In those cases, there is no option to choose a trusted UEFI file, however, there exists the option for a Customized Boot under the Boot Options menu. You have to add custom boot path and enter EFI\ubuntu\shimx64.efi. Then you have to change the boot priority and put Customized Boot on top of the list for UEFI Boot Order.

Addition to the answer of @Xeno you have to GO to "BOOT ORDER" and MOVE the "Custom Boot" at the top of "OS Boot" it should be like:

• USB
• Custom Boot
• Os Boot

It may be a lifesaver so I've felt the need to add this answer.