Where did the window come from, with which it is impossible to interact?

Question

Multimonitor

A window appeared on the monitor that I can not interact with

Answer 1

Reboot will save you. Should. If it doesn't help, clean the startup. Check for viruses.

Answer 2

Uncheck "Fade menu after command call" and "Fade effects" in Performance and you will be happy.

Answer 3

From chrome menu. Usually helps to kill all chrome processes (including background ones).