Black screen on Ubuntu Server 16.x

Due to the specifics of Ubuntu Server 16.x, sometimes, after booting the OS, instead of a command line prompt, there is a black screen. In fact, this is not a fatal system malfunction, but a minor annoying Ubuntu bug.

What to do:

On a virtual machine:

Press Alt+F2

On a physical server:

Press Ctrl+Alt+F2

Pressing these keys will cause a transition to the second virtual console.