Updated to MacOS 10.3.14 but won't log in

My mac os version is 10.3.14.

When I start my macbook pro 2016 with touchbar, it prompts with "A critical update is required for your mac" with a screen to connect to a network.

When I connect via WiFi/ethernet, it says "A critical update is required... But an error was encountered while installing this update.

Things I've tried:

- boot command+r

- boot command+option+r

- boot safe mode (which works, but on restart has the same problem)

- remove item groups

- erase nvram

- reset smc