GnuCash fails to start showing only a blank dialog

When starting GnuCash, a blank dialog is displayed and nothing else. The shape and position of the dialog indicates that it would be the tip of the day displayed on startup. The journalctl output includes the following, which may be relevant:

Jul 20 17:10:27 donald-Lemur org.gnome.zeitgeist.Engine[1383]: ** (zeitgeist-datahub:2095): WARNING **: zeitgeist-datahub.vala:212: Error during inserting events: GDBus.Error:org.gnome.zeitgeist
Jul 20 17:12:25 donald-Lemur com.canonical.Unity.Scope.Applications[1383]: Gtk-Message: GtkDialog mapped without a transient parent. This is discouraged.
Jul 20 17:12:49 donald-Lemur org.gnome.zeitgeist.Engine[1383]: ** (zeitgeist-datahub:2095): WARNING **: zeitgeist-datahub.vala:212: Error during inserting events: GDBus.Error:org.gnome.zeitgeist
Jul 20 17:12:49 donald-Lemur com.canonical.Unity.Scope.Applications[1383]: /usr/share/apport/apport-gtk:16: PyGIWarning: Wnck was imported without specifying a version first. Use gi.require_vers
Jul 20 17:12:49 donald-Lemur com.canonical.Unity.Scope.Applications[1383]: from gi.repository import GLib, Wnck, GdkX11, Gdk

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: gnucash 1:2.6.12-1
ProcVersionSignature: Ubuntu 4.4.0-31.50-generic 4.4.13
Uname: Linux 4.4.0-31-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CurrentDesktop: Unity
Date: Wed Jul 20 17:12:28 2016
EcryptfsInUse: Yes
ExecutablePath: /usr/bin/gnucash
ProcEnviron:
 PATH=(custom, no user)
 SHELL=/bin/bash
 LANG=en_US.UTF-8
 LANGUAGE=en_US
 XDG_RUNTIME_DIR=<set>
SourcePackage: gnucash
UpgradeStatus: No upgrade log present (probably fresh install)