Comment 2 for bug 1294209

This would probably be caused by the 4.11.4-1ubuntu1 release, of which the upstream changelog is:
4.11.4
======
[Please note that this is a development release.]

Fifth development release of xfdesktop targeting for Xfce 4.12.
Please report all problems at bugzilla.xfce.org.

* Versioned help:
  - Point to the docs.xfce.org page for xfdesktop 4.11. (Bug 10736)

* Build errors with some compiler flags:
  - dbus-glib is now required. Since xfconf requires it and
    xfconf is already required for xfdesktop, this shouldn't
    change dependancies much for xfdesktop. This bug was reported
    and fixed by Samuli Suominen. (Bug 10745)
  - Another build failure when disabling the menu and requiring
    exo was also resolved.

* Icon changes in the settings app:
  - Symbolic icons have issues with some gtk2 themes where they
    don't get colored properly. Additionally some themes don't
    have network-fs or gnome-dev-network so it has been changed
    gtk-network.

* Right click edits launchers:
  - When performing a right click, or shift + left click, on an item
    in the applications sub-menu of the desktop menu it will now pop
    up the dialog to edit the launcher. Same as xfce4-appfinder.

* Better migration from previous versions:
  - Xfdesktop now does a better job of migrating any user settings
    from 4.10 and before to the new xfconf properties.
  - Fix an settings issue when plug names aren't available

* Clean up some user strings:
  - Some tooltips end with a period, some do not. This has been
    unified.
  - "You are using more than one display, move this dialog to the
    display you want to edit the settings for." This takes a lot of
    space and brings along a bit of redundancy. Changed to "Move this
    dialog to the display you want to edit the settings for."
  - "Other items" on the third tab, below removable devices: "devices"
    replaces "items".
    Thanks to Harald Judt for pointing these issues out.

* Remember the window size of the settings dialog
  - Patch written by Harald Judt.

* Fix segfault on session start
  - Patch written by Thaddäus Tintenfisch

* Miscellaneous bug fixes:
  - Iconview theme/gtkrc color/style issues resolved.
  - Issues with folder cover art not loading have been fixed.
  - Make xfdesktop-settings pluggable again (Bug 10714)
  - Update the wallpapers after user sets folder in the settings
    app.
  - Minimize grid resizes, it now won't recalculate icon positions
    if the grid size didn't actually change.
  - Memory leaks fixed.
  - Warnings that happened during runtime have been fixed.
  - Fix a crash when removing displays
  - Show add/remove workspace option is on by default

* Translation updates: Bulgarian (bg), Chinese (Taiwan) (zh_TW),
  Croatian (hr), Danish (da), German (de), English (Australia) (en_AU),
  French (fr), Italian (it), Japanese (ja), Korean (ko), Malay (ms),
  Russian (ru), Serbian (sr), Spanish (Castilian) (es), Thai (th)