Thank you for proving the log files. Your graphics driver seems to have some issues:
[ 25.585] (II) [drm] nouveau interface version: 1.1.0 [ 25.585] (WW) Falling back to old probe method for vesa [ 25.585] (WW) Falling back to old probe method for modesetting [ 25.585] (WW) Falling back to old probe method for fbdev Therefore, I am moving this bug to the linux package (the issue is likely related to the Kernel's part of the graphics driver). The issue being in the graphics driver also supports the fact that your system crashes sometimes without opening Firefox or Thunderbird, as described in comment 7 of this report. Thanks. ** Package changed: firefox (Ubuntu) => linux (Ubuntu) ** Changed in: linux (Ubuntu) Status: Incomplete => New ** Summary changed: - System crashes when starting Firefox and/or Thunderbird + System usually crashes when starting Firefox and/or Thunderbird -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1176062 Title: System usually crashes when starting Firefox and/or Thunderbird To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1176062/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs