You have a fresh install UIM 20.4 and upgrade to 20.4 CU7 (May also happen on other CU releases) and you can't get content of Admin Console.
On the login page, you can log in, but the page is still "Loading" and not returning any results
Release : 20.4 CU.X
Outdated browser version
Verify if your browser is up to date - if not, update it to the most recent version.