Okay, I've done that. I'll log out and back in again. Actually, I rebooted, as I saw there was a kernel update I hadn't rebooted after applying. The reboot turned into the scary kind, for this Intel NUC, where I had to unplug not only all USB3 drives, but also the HDMI display before it would display the boot screen. But I'm back in action.
I'll let you know if there are further problems. All Firefox windows are correctly decorated now, and the untouchable FF window on the 2nd monitor is also dispalying and functioning again properly. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to metacity in Ubuntu. https://bugs.launchpad.net/bugs/1573478 Title: metacity (flashback) crashes and forces logout Status in metacity package in Ubuntu: Confirmed Bug description: After an update 2 or 3 days ago, at random times mid-session, all window decorations vanish, then the desktop goes to black (just time/date stamp showing IIRC, as at a screen lock), and then I'm presented with a login screen again. I was logging in with Gnome Flashback. It's been happening several times a day, and it's infuriating. This time I've logged in with the "(Metacity)" option rather than the (Flashback)" option, and I'll see if that works. Otherwise, I'll go back to a Window Maker session to get a reliable experience. I see this in /var/log/kern.log: Apr 22 18:31:48 pute kernel: [11401.021438] perf interrupt took too long (2509 > 2500), lowering kernel.perf_event_max_sample_rate to 50000 Apr 22 18:32:33 pute kernel: [11445.589519] show_signal_msg: 66 callbacks suppressed Apr 22 18:32:33 pute kernel: [11445.589528] metacity[2447]: segfault at 1a3359 ip 0000000000426f51 sp 00007fff3ed289b8 error 4 in metacity[400000+8d000] Apr 22 18:32:33 pute gnome-session-binary[1845]: Unrecoverable failure in required component metacity.desktop Apr 22 18:32:47 pute gnome-session-binary[7282]: Entering running state Apr 22 18:33:37 pute gnome-session-binary[8527]: Entering running state Here are some earlier ones: Apr 22 15:18:47 pute kernel: [60617.177188] metacity[16270]: segfault at 48 ip 0000000000426e2e sp 00007fff2daf0478 error 4 in metacity[400000+8d000] Apr 22 15:18:47 pute gnome-session-binary[16198]: Unrecoverable failure in required component metacity.desktop Apr 22 15:18:58 pute gnome-session-binary[28521]: Entering running state Apr 22 15:21:11 pute NetworkManager[802]: <info> [1461302471.2831] ModemManager disappeared from bus Apr 22 15:21:52 pute kernel: [ 0.000000] Initializing cgroup subsys cpuset Apr 22 02:22:23 pute kernel: [14028.678785] show_signal_msg: 27 callbacks suppressed Apr 22 02:22:23 pute kernel: [14028.678797] metacity[2509]: segfault at 302e64617074 ip 0000000000466780 sp 00007ffca8b8b998 error 4 in metacity[400000+8d000] Apr 22 02:22:28 pute gnome-session-binary[2439]: Unrecoverable failure in required component metacity.desktop Apr 22 02:22:56 pute gnome-session-binary[9411]: Entering running state Apr 22 04:02:03 pute kernel: [20008.941872] metacity[9467]: segfault at 7f6e008e0018 ip 0000000000426e20 sp 00007ffc7090a3c8 error 4 in metacity[400000+8d000] Apr 22 04:02:03 pute gnome-session-binary[9411]: Unrecoverable failure in required component metacity.desktop Apr 22 04:02:23 pute gnome-session-binary[14247]: Entering running state Apr 22 04:15:57 pute kernel: [20843.181807] traps: metacity[14309] general protection ip:466530 sp:7ffd40cb18b8 error:0 in metacity[400000+8d000] Apr 22 04:15:57 pute gnome-session-binary[14247]: Unrecoverable failure in required component metacity.desktop Apr 22 04:15:57 pute kernel: [20843.493120] QXcbEventReader[15628]: segfault at 7ff10d5e7629 ip 00007ff10d5e7629 sp 00007ff0ff5a5d60 error 14 in libes_plugin.so[7ff10d697000+6000] Apr 22 04:16:16 pute gnome-session-binary[16198]: Entering running state Apr 21 22:25:24 pute kernel: [3148119.324731] metacity[2822]: segfault at 100000007 ip 00007f8020e83278 sp 00007ffdc421c010 error 4 in libc-2.21.so (deleted)[7f8020e04000+1c0000] Apr 21 22:25:24 pute gnome-session-binary[2714]: Unrecoverable failure in required component metacity.desktop Apr 21 22:25:24 pute kernel: [3148119.901802] dconf worker[2727]: segfault at 8 ip 00007f35f3db2481 sp 00007f35ea99baa0 error 4 in libglib-2.0.so.0.4706.0 (deleted)[7f35f3d6b000+10e000] Apr 21 22:25:29 pute kernel: [3148124.830996] dbus-daemon[2635]: segfault at 0 ip 00007f10b2934017 sp 00007ffff7b10518 error 6 in libdbus-1.so.3.14.6 (deleted)[7f10b2908000+4a000] Apr 21 22:25:55 pute gnome-session-binary[19038]: Entering running state Apr 21 22:26:28 pute gnome-session-binary[19038]: Entering running state Apr 21 22:26:28 pute kernel: [3148183.865201] metacity[19100]: segfault at 48 ip 0000000000426f51 sp 00007ffe2a345168 error 4 in metacity[400000+8d000] Apr 21 22:26:32 pute gnome-session-binary[19038]: Unrecoverable failure in required component metacity.desktop Apr 21 22:26:48 pute gnome-session-binary[20075]: Entering running state Apr 21 22:27:31 pute gnome-session-binary[20075]: Entering running state $ lsb_release -rd Description: Ubuntu 16.04 LTS Release: 16.04 $ apt-cache policy metacity metacity: Installed: 1:3.18.3-1ubuntu3 Candidate: 1:3.18.3-1ubuntu3 Version table: *** 1:3.18.3-1ubuntu3 500 500 http://mirror.optus.net/ubuntu xenial/main amd64 Packages 100 /var/lib/dpkg/status 1:2.34.13-0ubuntu4.1 500 500 http://au.archive.ubuntu.com/ubuntu trusty-updates/main amd64 Packages What I expected to happen: No spontaneous, forced logout. What happened instead: Repeated, random forced logouts. ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: metacity 1:3.18.3-1ubuntu3 ProcVersionSignature: Ubuntu 4.4.0-21.37-generic 4.4.6 Uname: Linux 4.4.0-21-generic x86_64 ApportVersion: 2.20.1-0ubuntu2 Architecture: amd64 CurrentDesktop: GNOME-Flashback:Unity Date: Fri Apr 22 18:44:02 2016 InstallationDate: Installed on 2014-01-24 (819 days ago) InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Alpha amd64 (20140123) SourcePackage: metacity UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/metacity/+bug/1573478/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp

