mate-panel crashed with signal 7 in g_hash_table_foreach()

[Gene Soo]

1)
Description: Ubuntu Xenial Xerus (development branch)
Release: 16.04

2)
mate-panel:
  Installed: 1.12.1-1
  Candidate: 1.12.1-1
  Version table:
 *** 1.12.1-1 500
        500 http://us.archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status

3&4) Unknown Error after boot.

ProblemType: Crash
DistroRelease: Ubuntu 16.04
Package: mate-panel 1.12.1-1
ProcVersionSignature: Ubuntu 4.4.0-2.16-generic 4.4.0
Uname: Linux 4.4.0-2-generic x86_64
ApportVersion: 2.19.4-0ubuntu2
Architecture: amd64
CurrentDesktop: MATE
Date: Tue Feb 2 07:11:37 2016
ExecutablePath: /usr/bin/mate-panel
InstallationDate: Installed on 2016-02-01 (0 days ago)
InstallationMedia: Ubuntu-MATE 16.04 LTS "Xenial Xerus" - Alpha amd64 (20160201)
ProcCmdline: mate-panel
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
Signal: 7
SourcePackage: mate-panel
StacktraceTop:
 ?? () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
 g_hash_table_foreach () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
 gtk_rc_reset_styles () from /usr/lib/x86_64-linux-gnu/libgtk-x11-2.0.so.0
 g_closure_invoke () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
 ?? () from /usr/lib/x86_64-linux-gnu/libgobject-2.0.so.0
Title: mate-panel crashed with signal 7 in g_hash_table_foreach()
UpgradeStatus: No upgrade log present (probably fresh install)
UserGroups: adm cdrom dip lpadmin plugdev sambashare sudo

[Apport retracing service (apport)]

StacktraceTop:
 ?? ()
 ?? ()
 ?? ()
 ?? ()
 ?? ()