I am experiencing the same problem even after everything is config/galaxy.yml file correctly
Administrative users - set this to a comma-separated list of valid
Galaxy users (email addresses). These users will have access to the
Admin section of the server, and will have access to create users,
groups, roles, libraries, and more. For more information, see:
Galaxy Administration - Galaxy Community Hub
admin_users: xxxxxx@gmail.com
Force everyone to log in (disable anonymous access).
#require_login: false
I even tried to change the port to match the web interface port