Yesterday I could open any or all of the downloaded apps on the screen of my Apple laptop. Today, I can't! WHAT IS GOING ON? Being elderly and not very techie (to say the least!), I need simple answers, no jargon please. Is it because my laptop is 'elderly' in tech terms (Catalina 10.15.7) or what? I've used Mozilla most of the time for very many years, but I might swap to Safari or Chrome instead if this isn't sorted out PDQ.