Description of problem:

after manually running
$ sudo /usr/share/dnfdaemon/dnfdaemon-system -d -v --notimeout

I get a popup which reads:

DNF root backend was not authorized
Yum Extender will exit

If I run sudo yumex-dnf and run it as root it runs as expected.

Notes:
Linux localhost.localdomain 4.4.0-0.rc0.git2.1.fc24.i686 #1 SMP Wed Nov 4 18:35:57 UTC 2015 i686 i686 i386 GNU/Linux

installed from Fedora-Live-LXDE-i686-rawhide-20151105.iso
on a virtualbox 5.0.8 virtual machine
1024mb memory
10GB virtual disk

To duplicate this problem:
Install the iso
dnf install yumex-dnf
sudo /usr/share/dnfdaemon/dnfdaemon-system -d -v --notimeout
select Yumex-DNF from the Administration menu


Version-Release number of selected component:
dnfdaemon-0.3.10-1.fc24

Additional info:
reporter:       libreport-2.6.3
cmdline:        /usr/bin/python3 -tt /usr/share/dnfdaemon/dnfdaemon-system -d -v --notimeout
executable:     /usr/share/dnfdaemon/dnfdaemon-system
kernel:         4.4.0-0.rc0.git2.1.fc24.i686
runlevel:       N 5
type:           Python3
uid:            1000

Truncated backtrace:
connection.py:651:call_blocking:dbus.exceptions.DBusException: org.freedesktop.DBus.Error.AccessDenied: Connection ":1.89" is not allowed to own the service "org.baseurl.DnfSystem" due to security policies in the configuration file

Traceback (most recent call last):
  File "/usr/share/dnfdaemon/dnfdaemon-system", line 765, in <module>
    main()
  File "/usr/share/dnfdaemon/dnfdaemon-system", line 758, in main
    yd = DnfDaemon()
  File "/usr/share/dnfdaemon/dnfdaemon-system", line 63, in __init__
    bus_name = dbus.service.BusName(DAEMON_ORG, bus=dbus.SystemBus())
  File "/usr/lib/python3.4/site-packages/dbus/service.py", line 133, in __new__
    retval = bus.request_name(name, name_flags)
  File "/usr/lib/python3.4/site-packages/dbus/bus.py", line 303, in request_name
    'su', (name, flags))
  File "/usr/lib/python3.4/site-packages/dbus/connection.py", line 651, in call_blocking
    message, timeout)
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.AccessDenied: Connection ":1.89" is not allowed to own the service "org.baseurl.DnfSystem" due to security policies in the configuration file

Local variables in innermost frame:
get_args_opts: {'byte_arrays': False}
dbus_interface: 'org.freedesktop.DBus'
byte_arrays: False
message: <dbus.lowlevel.MethodCallMessage path: /org/freedesktop/DBus, iface: org.freedesktop.DBus, member: RequestName dest: org.freedesktop.DBus>
object_path: '/org/freedesktop/DBus'
timeout: -1.0
signature: 'su'
args: ('org.baseurl.DnfSystem', 0)
method: 'RequestName'
bus_name: 'org.freedesktop.DBus'
self: <dbus._dbus.SystemBus (system) at 0xb5302a1c>
kwargs: {}