1. Choose the key combination CTRL+ALT+DEL when it is not flashing, select “restart”.
  2. After this operation, the login window will appear on the terminal, but already with another virtual machine, which should not flash if it is not frozen.
  3. If the situation persists, go back to step one.

Logging out does not solve the problem, because after logging in again the user receives the same frozen machine, which will be repaired only after a forced restart.