Kubuntu crashes repeatedly without error notices

[yan]

Since about two weeks my system has repeatedly crashed completely without any error notice. The screen freezes and no keys respond. I have to shut down the computer pushing the button to turn it on for a couple of seconds. On reboot, I usually get the error message

PXE-E61: Media test failure, check cable
PXE-M0F: Exiting Intel Boot Agent

But usually Kubuntu boots after that without problems. Sometimes I have to Ctrl+Alt+Del to get boot going.

I have no idea what causes the crash, it happens suddenly and without any hint about what triggers it. I attach the content of /var/log/syslog right before the crash from a couple of times it happened.

I am running Kubuntu 16.04.3 LTS with Kernel 4.13.0-31 on a ThinkPad T460s.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

To change the source package that this bug is filed about visit https://bugs.launchpad.net/ubuntu/+bug/1745814/+editstatus and add the package name in the text box next to the word Package.

[This is an automated message. I apologize if it reached you inappropriately; please just reply to this message indicating so.]

[yan (yannn)]

Regarding the package: The problem is that I have no idea what causes the crash because there is no error message. That is why I filed the report for Ubuntu in general. I hope that is ok.

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1745814

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Joseph Salisbury (jsalisbury)]

Would it be possible for you to test the latest upstream kernel? Refer to https://wiki.ubuntu.com/KernelMainlineBuilds . Please test the latest v4.15 kernel[0].

If this bug is fixed in the mainline kernel, please add the following tag 'kernel-fixed-upstream'.

If the mainline kernel does not fix this bug, please add the tag: 'kernel-bug-exists-upstream'.

Once testing of the upstream kernel is complete, please mark this bug as "Confirmed".

Thanks in advance.

[0] http://kernel.ubuntu.com/~kernel-ppa/mainline/v4.15

[yan (yannn)]

Apport also aborts with an error:

$ apport-collect 1745814
dpkg-query: Kein Paket gefunden, das auf linux passt
Traceback (most recent call last):
  File "/usr/share/apport/apport-kde", line 530, in <module>
    sys.exit(UserInterface.run_argv())
  File "/usr/lib/python2.7/dist-packages/apport/ui.py", line 658, in run_argv
    return self.run_update_report()
  File "/usr/lib/python2.7/dist-packages/apport/ui.py", line 574, in run_update_report
    response = self.ui_present_report_details(allowed_to_report)
  File "/usr/share/apport/apport-kde", line 367, in ui_present_report_details
    desktop_info)
  File "/usr/share/apport/apport-kde", line 184, in __init__
    self.ui.ui_update_view(self)
  File "/usr/share/apport/apport-kde", line 358, in ui_update_view
    QTreeWidgetItem(keyitem, [str(line)])
UnicodeEncodeError: 'ascii' codec can't encode character u'\xe9' in position 21: ordinal not in range(128)
Segmentation fault (core dumped)

[yan (yannn)]

Re: #5

I just installed Kernel v4.15 and will see what happens. I will report back as soon as the problem appears or, if not, in a week or so.

Kernel v4.15 seems to fix another problem I had with an external monitor, great..

[yan (yannn)]

It seems this bug is fixed in the mainline kernel, since I installed Kernel 4.15, the problem did not reappear again.