Blank screen at boot - errors from Upstart on 16.04

Question

When I boot up, I see the x-windows where I can enter my login, then it gives me a blank desktop background where I see a mouse pointer and nothing else. I can switch to a TTY.

I get these errors on Ubuntu 15.10 and 16.04

$ cat ~/.xsession-errors
openConnection: connect: No such file or directory
cannot connect to brltty at :0
upstart: Failed to spawn upstart-udev-bridge main process: unable to execute: No such file or directory
upstart: unity-gtk-module pre-start process (1418) terminated with status 127
upstart: dbus pre-start process (1425) terminated with status 127

Any suggestions on what I could do?

Answer 1

I had the same problem. But it vanished once I did the following:

1. Ctrl+Alt+F1 to get to command line login.
2. Log in using user account you have setup during installation.
3. sudo apt-get update followed by sudo apt-get upgrade
4. reboot. When I logged in again, it worked.

Turns out many packages including upstart get upgraded with the bug fixed.

Hope this helps others.

Answer 2

I had altered my /etc/environment file and had this issue. The problem was that the PATH variable no longer could see the upstart-udev-bridge command because it is in/sbin. Replacing the line: PATH=$PATH:/bin:/sbin:/usr/bin:/usr/sbin at the top of that file fixed my issue.