just happened to me on trusty and the apport retracer duped my report to this ticket. I don't have any information how to trigger this bug, but for me it also happened on the next login after I did a general package update.
-- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xorg-server in Ubuntu. https://bugs.launchpad.net/bugs/1277985 Title: Xorg crashed with SIGABRT in OsAbort(no screens found) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xorg-server/+bug/1277985/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp