I installed a new DSpace server without much issue.
During the create-administrator step I made a mistake: I accidentally hit Enter-Enter past the admin email. I entered the other info correctly. The admin account was created successfully, just without an email address.
Once DSpace was up and running (using xmlui), I tried logging in as the admin with a blank email field and the admin password I entered – I was logged in successfully. (Not sure if this is the behavior you want).
I attempted to go to my Profile page to correct the email address, but the profile page was throwing an error – something about characters and XML, I assume because the email field was coming in empty. This is probably not expected behavior.
I was able to get around this by getting into psql directly as the dspace user and doing a simple update:
update eperson set firstname.lastname@example.org' where eperson_id=1;
Now the login with the new email works, along with the Profile page.