Getting the above error on boot is fairly scary. Thankfully, it’s not hard to fix. It probably means you have filled up your
/boot partition. In my case, I had 4 kernels/configs stored on there and it was right on 100%. Simply clean out the old ones – I keep the latest (obviously) and the one before, assuming it works. Then if you’re on ubuntu, issue:
dpkg-reconfigure linux-image-`uname -r`
To regenerate your initrd file, because if
/boot was full it was probably corrupt.