I have a Dell precision tower 3620 desktop, with Ubuntu 16.04 installed.
I have recently (today) updated it(not upgraded), and afterwards it asked for a reboot, so I did that. However, after reboot it showed the login screen and mentioned connection established (for internet through Ethernet), and login password cursor was blinking during that time but after that even the cursor stopped blinking and accepting no response from keyboard or mouse. Only one option is to force shutdown. I have no idea what part of the update resulted in this.
Everything was working fine before the update. Once the Ethernet icon announcing connection has been established goes away, it takes away the blinking of the cursor, then keyboard and mouse simply won't work. I even tried connecting keyboard on other slots, but no success. Can I uninstall the last update?
I heard a sound from the processor when login screen comes and in between the cursor also blinks, but once this sound is over then the blinking freezes and you have to forcibly shutdown, as this is an institute computer (I took the admin privilege, headache). Now I am really worried about it. How to fix it?
I did not have to go for a live USB, and I was able to go to grub
I was able to go to the GRUB menu by pressing the Esc key). This what I got.
I have no idea how to go about it after that. It is saying Secure boot forbids loading module, while loading Ubuntu I did secure boot by entering a password for that.