I've seen this bizarrely happen on a newly partitioned and custom installed Linux install, particularly if you did not properly unmount before rebooting.
You can find reports of it happening on various
How to fix the error: invalid arch-independent ELF magic.
You need to boot into Live/Rescue mode, chroot into your OS properly and then do a grub-install on each drive that nee........
There aren't too many simple guides that show you how to use commands to setup your USB or other drive as a normal bootable drive where you can easily boot custom kernels or whatever OS you would like.
1. Get the tools we need:
We install "syslinux" for MBR and "syslinux-efi" for EFI and "MBR" as we need a tool that embeds the actual MBR into our USB:
sudo apt install syslinux syslinux-efi mbr........
This was partitioned as a single 32GB VFAT but when I inserted it into the phone it said that it can't read it and now here is how the partition table looks. Interestingly enough the data works and reads fine from the computer still.
Disk /dev/sdb1: 32.1 GB, 32085360640 bytes
64 heads, 32 sectors/track, 30598 cylinders, total 62666720 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum........