Grub Error: invalid environment block. Press any key to continue

 Sometimes a rare error happened! when you boot up your system: about invalid environment block ... here you can learn how to resolve!

The error message appears immediately after the boot screen

There are two stages where can you resolve: the first one is if you can continue, then resolve it on boot screen time.

Press E at the GRUB menu. Find the line saying save_env recordfail and delete all of it with the Del or Backspace key. Press Ctrl+X to boot

The second way is a definitive way, run as root using doas or su commands:

cd /boot/grub
rm grubenv
grub-editenv grubenv create
grub-editenv grubenv set default=0
grub-editenv grubenv list

At this point of the last command you should see the string output of "default=0", then you can update grub configuration by running: update-grub command.