and hangs. postgresql works fine, installed yesterday from the Ubuntu repository.
I've tried removing ~/.pgadmin/pgadmin4.db, installing the packages pgadmin4-apache2 and python3-flask-babelex, setting SERVER_MODE=True and False, and resetting the postgres password.
I've never had pgadmin running before, and it's a vanilla install. Or at least it was until my various efforts to make it run, having googled around.