Random and sudden logging out from my user session

I've an issue with ubuntu 14.10 and 15.04. I'm logged out from my user session randomly and suddenly.

Here are some log information:

kern.log

first logout:

May  3 16:34:59 rm-work kernel: [28558.808129] traps: metacity[7712] trap int3 ip:7fe10cb50d00 sp:7ffdb4f06a00 error:0
May  3 16:34:59 rm-work gnome-session[7637]: Unrecoverable failure in required component metacity.desktop
May  3 16:35:12 rm-work gnome-session[30100]: Entering running state

second logout:

May  4 00:50:24 rm-work kernel: [54634.236474] traps: metacity[30179] trap int3 ip:7f68e3eddd00 sp:7ffc5e2b9d30 error:0
May  4 00:50:24 rm-work gnome-session[30100]: Unrecoverable failure in required component metacity.desktop
May  4 00:50:42 rm-work gnome-session[27957]: Entering running state

syslog.log

first log out:

May  3 16:34:59 rm-work gnome-session[7637]: Avertissement du gestionnaire de fenêtres : Log level 6: The program 'metacity' received an X Window System error.
May  3 16:34:59 rm-work gnome-session[7637]: This probably reflects a bug in the program.
May  3 16:34:59 rm-work gnome-session[7637]: The error was 'BadRegion (invalid Region parameter)'.
May  3 16:34:59 rm-work gnome-session[7637]: (Details: serial 63596288 error_code 140 request_code 138 (XFIXES) minor_code 12)
May  3 16:34:59 rm-work gnome-session[7637]: (Note to programmers: normally, X errors are reported asynchronously;
May  3 16:34:59 rm-work gnome-session[7637]: that is, you will receive the error a while after causing it.
May  3 16:34:59 rm-work gnome-session[7637]: To debug your program, run it with the GDK_SYNCHRONIZE environment
May  3 16:34:59 rm-work gnome-session[7637]: variable to change this behavior. You can then get a meaningful
May  3 16:34:59 rm-work gnome-session[7637]: backtrace from your debugger if you break on the gdk_x_error() function.)
May  3 16:34:59 rm-work kernel: [28558.808129] traps: metacity[7712] trap int3 ip:7fe10cb50d00 sp:7ffdb4f06a00 error:0
May  3 16:34:59 rm-work gnome-session[7637]: gnome-session[7637]: WARNING: Child process 7712 was already dead.
May  3 16:34:59 rm-work gnome-session[7637]: WARNING: Child process 7712 was already dead.
May  3 16:34:59 rm-work gnome-session[7637]: WARNING: Application 'metacity.desktop' killed by signal 5
May  3 16:34:59 rm-work gnome-session[7637]: WARNING: App 'metacity.desktop' respawning too quickly
May  3 16:34:59 rm-work gnome-session[7637]: gnome-session[7637]: WARNING: Application 'metacity.desktop' killed by signal 5
May  3 16:34:59 rm-work gnome-session[7637]: gnome-session[7637]: WARNING: App 'metacity.desktop' respawning too quickly
May  3 16:34:59 rm-work gnome-session[7637]: Unrecoverable failure in required component metacity.desktop
May  3 16:34:59 rm-work gnome-session[7637]: CRITICAL: We failed, but the fail whale is dead. Sorry....
May  3 16:34:59 rm-work gnome-session[7637]: gnome-session[7637]: CRITICAL: We failed, but the fail whale is dead. Sorry....

second log out:

May  4 00:50:24 rm-work gnome-session[30100]: Avertissement du gestionnaire de fenêtres : Log level 6: The program 'metacity' received an X Window System error.
May  4 00:50:24 rm-work gnome-session[30100]: This probably reflects a bug in the program.
May  4 00:50:24 rm-work gnome-session[30100]: The error was 'BadRegion (invalid Region parameter)'.
May  4 00:50:24 rm-work gnome-session[30100]: (Details: serial 170024023 error_code 140 request_code 138 (XFIXES) minor_code 12)
May  4 00:50:24 rm-work gnome-session[30100]: (Note to programmers: normally, X errors are reported asynchronously;
May  4 00:50:24 rm-work gnome-session[30100]: that is, you will receive the error a while after causing it.
May  4 00:50:24 rm-work gnome-session[30100]: To debug your program, run it with the GDK_SYNCHRONIZE environment
May  4 00:50:24 rm-work gnome-session[30100]: variable to change this behavior. You can then get a meaningful
May  4 00:50:24 rm-work gnome-session[30100]: backtrace from your debugger if you break on the gdk_x_error() function.)
May  4 00:50:24 rm-work kernel: [54634.236474] traps: metacity[30179] trap int3 ip:7f68e3eddd00 sp:7ffc5e2b9d30 error:0
May  4 00:50:24 rm-work gnome-session[30100]: gnome-session[30100]: WARNING: Child process 30179 was already dead.
May  4 00:50:24 rm-work gnome-session[30100]: WARNING: Child process 30179 was already dead.
May  4 00:50:24 rm-work gnome-session[30100]: gnome-session[30100]: WARNING: Application 'metacity.desktop' killed by signal 5
May  4 00:50:24 rm-work gnome-session[30100]: WARNING: Application 'metacity.desktop' killed by signal 5
May  4 00:50:24 rm-work gnome-session[30100]: WARNING: App 'metacity.desktop' respawning too quickly
May  4 00:50:24 rm-work gnome-session[30100]: gnome-session[30100]: WARNING: App 'metacity.desktop' respawning too quickly
May  4 00:50:24 rm-work gnome-session[30100]: Unrecoverable failure in required component metacity.desktop
May  4 00:50:24 rm-work gnome-session[30100]: CRITICAL: We failed, but the fail whale is dead. Sorry....
May  4 00:50:24 rm-work gnome-session[30100]: gnome-session[30100]: CRITICAL: We failed, but the fail whale is dead. Sorry....

Any idea to fix it?

Regards


This is unresolved, but relatively rare bug, if you are using gnome-flashback session. Partly because mostly all are using default UI. See more details and subscribe to see if problem is resolved here: https://bugs.launchpad.net/ubuntu/+source/xorg/+bug/1455916

Temporary fix - don't use gnome-flashback session.