I just now reinstalled ErpNext with v12.2.2. from install.py.
At the setup wizard, after setting language and region I get to the 3rd page that asks for Full Name, Email Address and Password.
As soon as the page opens a modal alert states Invalid Email: Administrator and automatically fills the Email Address field with Administrator. Then that field, the Password field and the Next button are all disabled!!
There is no way past that point
I have tried completely clearing cookies, caches, local storage, etc. but each page change refills the same context data.
I should have realized that that was something to try, but using Chrome Dev Tools I was clearing all storage, cookies etc. Apparently, even that is not enough.