In my case firefox when firefox is stuck with no visible window but a zombie process (as happens every so often for unknown reasons) I also get this message.
Via xlsclient I do find a firefox 10x10 pixels unmapped window that is not visible anywhere (the Unity dock doesn't find it either). The output of xwininfo is attached. The user interaction design is very poor: in this case the dialog should either: (a) offer a "kill and retry" button (b) detect the hung firefox and do a kill and retry silently, counting the retries to avoid an endless retry loop, and only when that procedure has failed show the dialog there is in this case no reason to force the user to "restart the system" to emulate the mediocrity of the Windows user experience. xwininfo: Window id: 0x1800001 "Firefox" Absolute upper-left X: 10 Absolute upper-left Y: 10 Relative upper-left X: 10 Relative upper-left Y: 10 Width: 10 Height: 10 Depth: 24 Visual: 0x20 Visual Class: TrueColor Border width: 0 Class: InputOutput Colormap: 0x22 (installed) Bit Gravity State: NorthWestGravity Window Gravity State: NorthWestGravity Backing Store State: NotUseful Save Under State: no Map State: IsUnMapped Override Redirect State: no Corners: +10+10 -1900+10 -1900-1180 +10-1180 -geometry 10x10+10+10 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/401674 Title: Firefox running and not responding To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox-3.0/+bug/401674/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
