After installing sts2019-kb4462171-fullfile-x64-glb ( Feb 2019 CU), midway during the installation and afterwards you cannot log into central admin page.
For example, if you log into /_layouts/15/settings.aspx, you will receive a 404 error not found message.
Impact- Admins will not be able to access Central admin site after new CU is installed, and will be forced to run PSConfig..
Central admin web site in (IIS Manager)
Before running PSConfig, you will only see
_admin
After running PSConfig, you will see both
_admin
_adminroot
After running PSConfig,exe, you will see that the central admin web site has been changed to