Comment 1 for bug 281967

The same for me.
kbluetooth4-devicemanager can't connect with kbluetooth4:
kbluetooth4-devicemanager(7101) Solid::Control::ManagerBasePrivate::loadBackend: Backend loaded: "BlueZ"
process 7101: arguments to dbus_message_new_method_call() were incorrect, assertion "path != NULL" failed in file dbus-message.c line 1070.
This is normally a bug in some application using the D-Bus library.
QDBusConnection: error: could not send message to service "org.bluez" path "" interface "org.freedesktop.DBus.Introspectable" member "Introspect"
kbluetooth4-devicemanager(7101) DeviceMan::DeviceMan: Device Manager - Welcome
kbluetooth4-devicemanager(7101) DeviceMan::getConfiguredDevices: Device List Size: 0
kbluetooth4-devicemanager(7101) DeviceMan::slotStartWizard: Starting Wizard
kbluetooth4-wizard(7106) Solid::Control::ManagerBasePrivate::loadBackend: Backend loaded: "BlueZ"
process 7106: arguments to dbus_message_new_method_call() were incorrect, assertion "path != NULL" failed in file dbus-message.c line 1070.
This is normally a bug in some application using the D-Bus library.
QDBusConnection: error: could not send message to service "org.bluez" path "" interface "org.freedesktop.DBus.Introspectable" member "Introspect"
Object::connect: No such slot BTWizard::slotValidatePage()
kbluetooth4-wizard(7106) BTWizard::slotNext: Page ID: 1
kbluetooth4-wizard(7106) BTWizard::slotNext: Page ID: 2
kbluetooth4-wizard(7106) BTWizard::slotNext: page 2 reached!
kbluetooth4-wizard(7106) BTWizard::slotSearch: searching...
process 7106: arguments to dbus_message_new_method_call() were incorrect, assertion "path != NULL" failed in file dbus-message.c line 1070.
This is normally a bug in some application using the D-Bus library.
QDBusConnection: error: could not send message to service "org.bluez" path "" interface "org.bluez.Adapter" member "DiscoverDevices"
kbluetooth4-wizard(7106) BTWizard::~BTWizard: Deleting Wizard
kbluetooth4-devicemanager(7101) DeviceMan::~DeviceMan: inputDeviceMap deleted
kbluetooth4-devicemanager(7101) DeviceMan::~DeviceMan: remoteDeviceMap deleted
kbluetooth4-devicemanager(7101) DeviceMan::~DeviceMan: Device Manager closed

DBus is working:
katoda@compal ~ $ ps aux | grep dbus
105 4974 0.0 0.0 3040 1360 ? Ss 07:42 0:00 /bin/dbus-daemon --system
root 5689 0.0 0.0 3124 680 ? S 07:43 0:00 dbus-launch --autolaunch 19452e83451b572343b675ec48f6e5fe --binary-syntax --close-stderr
root 5692 0.0 0.0 2640 728 ? Ss 07:43 0:00 //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session
katoda 5750 0.0 0.0 3532 960 ? Ss 07:43 0:00 /usr/bin/ck-launch-session /usr/bin/dbus-launch --exit-with-session x-session-manager
katoda 5791 0.0 0.0 4740 636 ? Ss 07:43 0:00 /usr/bin/ssh-agent /usr/bin/ck-launch-session /usr/bin/dbus-launch --exit-with-session x-session-manager
katoda 5808 0.0 0.0 3124 672 ? S 07:43 0:00 /usr/bin/dbus-launch --exit-with-session x-session-manager
katoda 5809 0.0 0.0 2904 1100 ? Ss 07:43 0:00 //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session
root 6615 0.0 0.0 3124 704 ? S 07:52 0:00 dbus-launch --autolaunch 19452e83451b572343b675ec48f6e5fe --binary-syntax --close-stderr
root 6616 0.0 0.0 2640 760 ? Ss 07:52 0:00 //bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session