Hi,
Today (25.12.08.) my system did a whole system upadate. It was about 2,8Gb - kernel, plasma, nvidia, etc. Everything went fine. After this pacman asked reboot. I did. After reboot the boot stoped and got this massage:
error: symbol grub_memcpy not found
entering rescue mode…
grub rescue>
What to do? Thank you
Try this:
Yep. Thank you for the suggestion. I got this and used chatgpt for more detailed help. I takes one hour - but now it works. Thank you 
I faced the same issue today after the upgrade on the stable branch. The core reason seems to be that there is obviously a problem with the case of the folder and file names in the efi/ folder. They have been all lower case on my system, i.e. the important full path read /boot/efi/EFI/boot/bootx64.efi instead of the correct version: /boot/efi/EFI/BOOT/BOOTX64.EFI
So basically it is sufficient to mount your boot partition and correct the case of the folder and file accordingly. After that, everything was back to normal.
Had the same issue. I was able fix it in the BIOS settings. In the boot section, there was “UEFI OS“ as first priority and “Manjaro“ as second. I set “Manjaro“ the to be the first in boot order and was able to fully boot to desktop.
This is - most likely - caused by the loader designated as the first in the systems firmware NOT being the Manjaro Linux efi-stub but the default grub which is not in sync with the available grub configuration.
The Manjaro Linux specific helper script install-grub is designed to handle this - the default GRUB and Manjaro Linux efi-stub must be binary identical to ensure they both understand the grub configuration.
In real world - this means
/boot/efi/EFI/Manjaro/grubx64.efi/boot/efi/EFI/boot/bootx64.efiSo to be binary identical - even the different names - the casing should be irrelevant but some firmware may expect a specific casing for the default entry.
sudo cp /boot/efi/EFI/Manjaro/grubx64.efi /boot/efi/EFI/BOOT/BOOTx64.efi
Technically - the FAT32 file system is case insensitive - but some firmware has a hardcoded path - where the casing matters.
Also on Linux the casing matters - but this is caused by rules applied on the mount point itself.
You can also find an excellent collection of troubleshooting tips on
How did you solve it?
I got this error when I boot: The system found unauthorized changes on the firmware, operating system or UEFI drivers.
Scroll up to the marked solution and be illuminated. 
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