I have tried this, but I am not able to open Anki in any mode or to close it. I have restarted the computer several times, but Anki is still open and asking if I want to install available add-ons; and I cannot chose OK or cancel or close the window. Is there any other way to fix this?
When you restart your computer, before Anki opens, right click on it in the dock and force quit the application.
To do this, when your computer (Iβm assuming you are using a macbook?), right click on Anki in your dock, hold the Command button β you will see βForce quitβ β click on it β that should fully quit Anki