I had upgraded to MacOS Catalina on my 2015 Macbook Pro yesterday, and things were working fine when I left it to sleep yesterday. Today morning, I find that the keyboard and trackpad were not working (except for the power button) and hence I was usable to login. (Unable to enter the password). Tried restarting using the power button, still same. Restarted again, and it went to recovery (?) OS and it’s showing me a grey screen, with alternating images of what looks like the underside of a mouse, and a laptop’s side. There is an arrow, asking to slide a notch. Stuck here. Can someone explain what this screen is, and hopefully a way to get out of this?