It also happened for me without onboard or xprop, just by pressing alt- tab and then doing "something" that the switcher didn't like.
Attached is the output of xininfo -root -tree when this happened. ** Attachment added: "broken-alt-tab" https://bugs.launchpad.net/unity/+bug/832033/+attachment/2396147/+files/broken-alt-tab -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/832033 Title: window switcher stuck when alt-tab with Onboard To manage notifications about this bug go to: https://bugs.launchpad.net/unity/+bug/832033/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs