How to close window when installing ubuntu?

Question

linux

When installing Ubuntu, such an incomprehensible window popped up. When you click OK or click on the cross, nothing happens.

Answer 1

Try to open the console, type xkill and hover over this window.

Answer 2

Ctrl-Alt-Esc not working? If it works, the cursor changes to a skull and crossbones icon. You need to point it at the window and click.