unity-settings-daemon crashed with SIGABRT in g_assertion_message()

Logged in, Unity appeared to not start. This was the first crash, but not sure if it was actually the root cause.

ProblemType: Crash
DistroRelease: Ubuntu 15.04
Package: unity-settings-daemon 15.04.1+15.04.20150324.1-0ubuntu1
ProcVersionSignature: Ubuntu 3.19.0-11.11-generic 3.19.3
Uname: Linux 3.19.0-11-generic x86_64
ApportVersion: 2.17-0ubuntu1
Architecture: amd64
CurrentDesktop: Unity
Date: Thu Apr 2 09:20:08 2015
EcryptfsInUse: Yes
ExecutablePath: /usr/lib/unity-settings-daemon/unity-settings-daemon
InstallationDate: Installed on 2014-03-09 (388 days ago)
InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140304)
ProcCmdline: /usr/lib/unity-settings-daemon/unity-settings-daemon
ProcEnviron:
 PATH=(custom, user)
 SHELL=/bin/bash
 LANG=en_AU.UTF-8
 LANGUAGE=en_AU:en
 XDG_RUNTIME_DIR=<set>
Signal: 6
SourcePackage: unity-settings-daemon
StacktraceTop:
 g_assertion_message () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 g_assertion_message_expr () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 gsd_rr_config_load_current () from /usr/lib/libunity-settings-daemon.so.1
 gsd_rr_config_new_current () from /usr/lib/libunity-settings-daemon.so.1
 gsd_rr_config_load_filename () from /usr/lib/libunity-settings-daemon.so.1
Title: unity-settings-daemon crashed with SIGABRT in g_assertion_message()
UpgradeStatus: Upgraded to vivid on 2014-06-07 (298 days ago)
UserGroups: adm cdrom dialout dip libvirtd lpadmin plugdev sambashare sbuild sudo vboxusers