Update produces errors, kernel headers missing

[stephane]

you have to remove all files from kernels 5.7 and 5.8
see this

How to remove a "ghost-kernel"?

@ Graham: No, i never used Grub Customizer @ stephane: $ sudo ls /etc/mkinitcpio.d/*.preset /etc/mkinitcpio.d/linux510.preset /etc/mkinitcpio.d/linux58.preset /etc/mkinitcpio.d/linux54.preset $ sudo ls /boot/* /boot/initramfs-5.10-x86_64-fallback.img /boot/intel-ucode.img /boot/initramfs-5.10-x86_64.img /boot/linux510-x86_64.kver /boot/initramfs-5.4-x86_64-fallback.img /boot/linux54-x86_64.kver /boot/initramfs-5.4-x86_64.img /boot/vmlinuz-5.10-x86_64 /boot/initramfs-5.8-x86_64-fallb…