this was my output, and it gave me a white screen
sam@sam-laptop:~$ unity
** (unity:3289): WARNING **: Unable to find the file menu stock item
** (unity:3289): DEBUG: New Desktop Window: 1400029
** (unity:3289): DEBUG: Evaluating bitmask for '%l:%M %p'
** (unity:3289): DEBUG: Checking against 2 posible times
** (unity:3289): DEBUG: Guessing max time width: 53
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): libunity-private-DEBUG: unity_gesture_xcb_dispatcher_glue_init
(unity:3289): GLib-GObject-WARNING **: invalid cast from `BamfApplication' to `BamfWindow'
** (unity:3289): CRITICAL **: bamf_window_get_window_type: assertion `BAMF_IS_WINDOW (self)' failed
(unity:3289): GLib-GObject-WARNING **: invalid cast from `BamfApplication' to `BamfWindow'
** (unity:3289): CRITICAL **: bamf_window_get_window_type: assertion `BAMF_IS_WINDOW (self)' failed
** (unity:3289): DEBUG: New Desktop Window: 1400029
(unity:3289): GLib-GObject-WARNING **: invalid cast from `BamfApplication' to `BamfWindow'
** (unity:3289): CRITICAL **: bamf_window_get_window_type: assertion `BAMF_IS_WINDOW (self)' failed
** (unity:3289): DEBUG: Looking for parent window on XID 39845893
** (unity:3289): DEBUG: Switching to menus from XID 39845893
** (unity:3289): DEBUG: Unable to get MWM functions for: 39845893
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): libunity-private-DEBUG: test-window.vala:295: This target does not support getting window details
** (unity:3289): DEBUG: Registering window ID 20971561 with path /org/ayatana/menu/1400029 from :1.30
** (unity:3289): DEBUG: Creating new windows menu: 1400029, :1.30, /org/ayatana/menu/1400029
** (unity:3289): DEBUG: Setting Desktop Menus to: 1400029
** (unity:3289): DEBUG: Looking for parent window on XID 39845893
** (unity:3289): DEBUG: Switching to menus from XID 39845893
** (unity:3289): DEBUG: Registering window ID 67108939 with path /org/ayatana/menu/400004B from :1.88
** (unity:3289): DEBUG: Creating new windows menu: 400004B, :1.88, /org/ayatana/menu/400004B
** (unity:3289): DEBUG: Looking for parent window on XID 39845893
** (unity:3289): DEBUG: Switching to menus from XID 39845893
** (unity:3289): DEBUG: Registering window ID 39845893 with path /org/ayatana/menu/2600005 from :1.132
** (unity:3289): DEBUG: Creating new windows menu: 2600005, :1.132, /org/ayatana/menu/2600005
** (unity:3289): DEBUG: Switching to menus from XID 39845893
(unity:3289): Gtk-WARNING **: gtk_menu_detach(): menu is not attached
(unity:3289): Indicator-Application-DEBUG: Connected to Application Indicator Service.
(unity:3289): Indicator-Application-DEBUG: Setup proxy signals
(unity:3289): Indicator-Application-DEBUG: Connect to them.
(unity:3289): Indicator-Application-DEBUG: Request current apps
** (unity:3289): DEBUG: New Desktop Window: 5600008
(unity:3289): Indicator-Application-DEBUG: Building new application entry: :1.28 with icon: bluetooth-active
** (unity:3289): DEBUG: Updating username label
** (unity:3289): DEBUG: Using user icon for 'Guest Session' from file: (null)
** (unity:3289): DEBUG: Username width 21px
** (unity:3289): DEBUG: Font size 9.000000 pt
** (unity:3289): DEBUG: Screen DPI 96.000000
** (unity:3289): DEBUG: Username width 1.750000em
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
(unity:3289): LIBDBUSMENU-GLIB-CRITICAL **: dbusmenu_menuitem_property_get_value: assertion `DBUSMENU_IS_MENUITEM(mi)' failed
** (unity:3289): DEBUG: new_application_item ("Chat")
** (unity:3289): DEBUG: new_application_item ("Mail")
** (unity:3289): DEBUG: new_application_item ("Compose New Message")
** (unity:3289): DEBUG: new_application_item ("Contacts")
** (unity:3289): DEBUG: new_application_item ("Broadcast")
** (unity:3289): DEBUG: entry hint: Post message...
** (unity:3289): DEBUG: entry_maybe_show_hint, nothing in the entry or not focused, so setting the hint to: Post message...
(unity:3289): GLib-GObject-WARNING **: /build/buildd/glib2.0-2.26.0/gobject/gsignal.c:2275: signal `destroy' is invalid for instance `0x9926e00'
** (unity:3289): WARNING **: Entry has no children!
** (unity:3289): WARNING **: Entry has no children!
** (unity:3289): WARNING **: Entry has no children!
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
(unity:3289): GLib-GObject-WARNING **: invalid (NULL) pointer instance
(unity:3289): GLib-GObject-CRITICAL **: g_signal_connect_object: assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
Mesa 7.9-devel implementation error: Bad renderbuffer format: 21
Please report at bugzilla.freedesktop.org
(unity:3289): libunity-private-DEBUG: test-window.vala:295: This target does not support getting window details
^C
sam@sam-laptop:~$
Thanks for trying unity and reporting this bug.
Please, do use "$ ubuntu-bug unity" to report unity bugs so that we can have all necessary infos.
For instance, in that case, what's your graphic card?