openSUSE Leap 15.0
SDDM Version: 0.17.0-lp150.9.6.1

SDDM issue #1066 <https://github.com/sddm/sddm/issues/1066> states:
"That one loads quite a lot of stuff - please try a different theme such as the
builtin one (just don't set theme=). If it does not happen anymore, open a
bugreport for the plasma theme."

Leap 15.0 systemd Journal contains the following "QObject: Cannot create
children for a parent that is in a different thread." related entries:

Sep 28 09:58:58 xxx sddm-helper[2462]: pam_unix(sddm-greeter:session): session
opened for user sddm by (uid=0)
Sep 28 09:58:58 xxx sddm[2436]: Greeter session started successfully
Sep 28 09:58:58 xxx sddm-greeter[2470]: High-DPI autoscaling not Enabled
Sep 28 09:58:58 xxx sddm-greeter[2470]: Reading from
"/usr/share/xsessions/icewm.desktop"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Reading from
"/usr/share/xsessions/plasma5.desktop"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Reading from
"/usr/share/xsessions/twm.desktop"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Reading from
"/usr/share/xsessions/xsession.desktop"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Reading from
"/usr/share/wayland-sessions/plasmawayland.desktop"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Loading theme configuration from
"/usr/share/sddm/themes/breeze-openSUSE/theme.conf"
Sep 28 09:58:58 xxx sddm-greeter[2470]: Connected to the daemon.
Sep 28 09:58:58 xxx sddm[2436]: Message received from greeter: Connect
Sep 28 09:58:58 xxx sddm-greeter[2470]: Loading
file:///usr/share/sddm/themes/breeze-openSUSE/Main.qml...
Sep 28 09:58:58 xxx sddm-greeter[2470]: QObject: Cannot create children for a
parent that is in a different thread.
Sep 28 09:58:58 xxx sddm-greeter[2470]: QObject: Cannot create children for a
parent that is in a different thread.
Sep 28 09:58:58 xxx sddm-greeter[2470]: QObject: Cannot create children for a
parent that is in a different thread.
Sep 28 09:58:58 xxx sddm-greeter[2470]: QObject::installEventFilter(): Cannot
filter events for objects in a different thread.
Sep 28 09:58:58 xxx sddm-greeter[2470]: QObject: Cannot create children for a
parent that is in a different thread.
Sep 28 09:58:59 xxx sddm-greeter[2470]: QObject: Cannot create children for a
parent that is in a different thread.
Sep 28 09:58:59 xxx sddm-greeter[2470]: QObject::installEventFilter(): Cannot
filter events for objects in a different thread.
Sep 28 09:58:59 xxx dbus-daemon[1062]: [system] Activating via systemd: service
name='org.freedesktop.UDisks2' unit='udisks2.service' requested by ':1.25'
(uid=381 pid=2470 comm="/usr/bin/sddm-greeter --socket /tmp/sddm-:0-TzoLar")
Sep 28 09:58:59 xxx dbus-daemon[1062]: [system] Activating via systemd: service
name='org.freedesktop.UPower' unit='upower.service' requested by ':1.25'
(uid=381 pid=2470 comm="/usr/bin/sddm-greeter --socket /tmp/sddm-:0-TzoLar")
Sep 28 09:59:00 xxx sddm-greeter[2470]: Adding view for "DVI-0" QRect(0,0
1920x1080)
Sep 28 09:59:00 xxx sddm-greeter[2470]: QDBusConnection: name
'org.freedesktop.UDisks2' had owner '' but we thought it was ':1.26'
Sep 28 09:59:00 xxx sddm-greeter[2470]: Message received from daemon:
Capabilities
Sep 28 09:59:00 xxx sddm-greeter[2470]: Message received from daemon: HostName
Sep 28 09:59:04 xxx sddm-greeter[2470]: Reading from
"/usr/share/xsessions/xsession.desktop"