Hello.
I was upgrading RoutersOS from version 7.22 to 7.23.1 on an x86 server based on a Dell R630, and the bootloader somehow became corrupted, preventing the system from booting. The server uses a WD Blue 1TB hard drive (WD10SPZX) connected via the integrated SATA controller. The hard drive is only a year old. I compared the contents of the bootloader /EFI/BOOT/BOOTX64.EFI with a similar file from the same firmware version, and many sections were empty. I initially tried replacing the file using a boot image with a UEFI shell, but an I/O error prevented this. Then I booted with GParted Live, and the BOOTX64.EFI file was completely empty, but this time I was able to overwrite it. After that, the system booted correctly.
Has anyone encountered this behavior or have any ideas about the reasons for this behavior?