Using 16.04 had the same problem with blank screen. The first thing I tried was running 'unity-tweak-tool --reset-unity' but that made it even worse: before the windows had borders & top bar and I could use some shortcuts such as ctrl-alt-T to pull up gnome-terminal (but not custom shortcuts) and alt-tab to switch screens but that was lost after that command.
Removing ~/.config/dconf/user made it work again as noted above, but specifically something in /org/compiz since running 'dconf reset -f /org/compiz/' worked too. I then reverted back to the problematic file and tried resetting /org/compiz/profiles/unity and the only thing that fixed was the alt- tab, shortcuts and window borders again. So there seems to be another bug since shortcuts are located in org/gnome/settings-daemon/plugins /media-keys Running 'gnome-session-quit --force' gets an error which normally doesn't happen when it's working normally: ** (gnome-session-quit:3002): WARNING **: Failed to call logout: GDBus.Error:org.gnome.SessionManager.NotInRunning: Logout interface is only available during the Running phase Attached is a dconf dump of /org/compiz ** Attachment added: "dconf /org/compiz/ dump" https://bugs.launchpad.net/ubuntu/+source/at-spi2-core/+bug/1285444/+attachment/4681188/+files/dconf_org-compiz.txt -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to at-spi2-core in Ubuntu. https://bugs.launchpad.net/bugs/1285444 Title: Login Successful, Desktop Never Loads Status in at-spi2-core package in Ubuntu: Triaged Bug description: Here is what I encounter 1. Boot computer, boot proceeds normally 2. Reach standard Ubuntu login screen, nothing seems to be amiss 3. Enter user name and password 4. Login disappears, just see the pink "Ubuntu 14.04" background The desktop never loads, not even after ~30 minutes. The launcher never appears, and the Desktop background never changes to the user- configured background. Other features: * Cursor works fine, it can be moved around the screen * No error messages pop up * ALT+F1 etc. can be used to switch to different TTYs; all files on the system appear to be intact * Print screen button works (I will upload a screen shot when I get a chance to copy it onto a USB drive) * Hitting power button pops up a window prompting the user to decide whether to shut down * CTRL+ALT+DELETE prompts the user to log out * Desktop does not load on any user accounts, including the guest account To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/at-spi2-core/+bug/1285444/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp