I just updated my macOS and I can’t log in

You’d have to start up from Recovery Partition by restarting and holding down Apple ( command) + R keys in startup… from there, pick a language & continue. Move your cursor( the arrow) to the top center of your screen and click. You should see MacOs X Tools. Go to Terminal and get that going. Type in “resetpassword” without the quote marks. Press enter/return on your keyboard. This gets you into the main login/admin password reset application.

hope this helps

john b

Try zapping the pram 3-4 times on startup… on an Intel mac , hold down Apple + Option key+P+R keys on the keyboard together on startup for 4 chimes/bongs then let your Mac boot up as per usual. Usually if you have an iPhone/iPad as well as the Mac, you can use it as a trusted device to help with the 6 digit recovery code… usually you can get apple to text you/call you with a new code… asssuming you have 2factor authentication turned on and a cellphone number/email associated with your apple ID account

john b