Are you still seeing this issue after updating unity to 7.4.0+16.04.20160801.2-0ubuntu1 ? https://bugs.launchpad.net/ubuntu/+source/unity/+bug/1605012 is supposed to have addressed the crash.
** Changed in: compiz (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1612059 Title: Unable to switch language on login/lock screen with shortcut keys of Alt+Shift Left To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/1612059/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs