Today I've upgraded to Ubuntu 15.10 using Ubuntu "Software Update". The download and installation went fine, till I did a restart. At some point the boot stops and the shift-lock LED is blinking on the keyboard. I've selected the recovery entry in the grub and then the following error message can be seen:
kernel panic not syncing unable to mount root fs on unkonown-block(0,0)
What can I do to fix this error?
If I boot older grub entries like kernel 3.19.0-31 it works.