Apple has just released several updates to their various operating systems. I have installed most of them without incident. The Big Sur 11.3.1 update has some fixes to the Webkit. The Webkit is used by different things in the OS, but mostly by the Safari web browser. As far as I am concerned, I do so much work with Safari any update that involves security is an automatic installation. The Big Sur update involves several restarts, and it took quite a while.