gnome-control-center doesn't start

[Tomasz Majchrzak]

gnome-control-center doesn't start. There is no crash, core dump, etc.

This bit in syslog (/var/log/syslog) gives us some information:

gnome-control-c[2962]: invalid unclassed pointer in cast to 'GtkWindow'
gnome-control-c[2962]: gtk_window_present_with_time: assertion 'GTK_IS_WINDOW (window)' failed

Actually something similar has been seen already in the past but it hasn't been resolved:

https://bugs.launchpad.net/ubuntu/+source/gnome-control-center/+bug/1745846

I might not be the only person affected:

https://askubuntu.com/questions/1094442/gnome-control-center-disappears-on-ubuntu-18-10-after-repostioning-ubuntu-dock/1098815#1098815

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: gnome-control-center 1:3.28.2-0ubuntu0.18.04.2
ProcVersionSignature: Ubuntu 4.15.0-42.45-generic 4.15.18
Uname: Linux 4.15.0-42-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CurrentDesktop: GNOME-Flashback:GNOME
Date: Thu Dec 6 11:08:42 2018
InstallationDate: Installed on 2018-11-26 (9 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
SourcePackage: gnome-control-center
UpgradeStatus: No upgrade log present (probably fresh install)

[Tomasz Majchrzak (tmajchrzak)]

It works fine after reboot. I cannot reproduce it.

[Sebastien Bacher (seb128)]

Could you include your journalctl log from the session having the issue?

[Sebastien Bacher (seb128)]

Do you still got the issue? It could be useful to have a backtrace as described on https://wiki.ubuntu.com/Backtrace using 'gnome-control-center --g-fatal-warnings'

Your log has a mention of trying to open the online accounts panel and failing and the corresponding service has regular warnings
'goa-daemon[1349]: goa_ews_client_autodiscover() failed: 2 — Error resolving “autodiscover.outlook.office365.com”: Name or service not known'

UNsure if that has to to do. If the issue is with this panel maybe calling 'gnome-control-center keyboard' (or another panel) would make it open?

[Tomasz Majchrzak (tmajchrzak)]

I would not be worried about this message. I had issues to configure my email account correctly (access to Office365 via EWS) but eventually I succeeded to set it up. I created the new online account and I closed the control center. Then it worked in my Evolution client. Later the same day I tried to go to control center again to change other settings but I couldn't open it.

I cannot reproduce it again. My best guess for the scenario is:

1. Configure new EWS account in control-center panel.
2. Close the panel.
3. Try to start it again.

I cannot try it again as I have just one EWS-capable account. I don't want to delete it from the settings because it would probably delete my local mailbox and I would lose all my configuration.

I don't think unsuccessful email configuration has anything to do with this problem because it cannot be saved until connection to mail server is established.

[Sebastien Bacher (seb128)]

It's a bit tricky to debug it/know more without a backtrace of a system having the issue. Let's see if you/someone hits that again
Oh, also the online accounts are by user, so you could probably try adding it again with a test user session if you don't want to delete your configuration

[Tomasz Majchrzak (tmajchrzak)]

Ok, I have tried again on the new account but I couldn't reproduce it again following the steps above. I have done a lot of other system configuration at the time it had happened to me, it might be tricky to get to this state again.

[Sebastien Bacher (seb128)]

Thanks for trying, well let's see if you get it again or if other users hit it. If not then it's probably low priority due to the low frequency, if we get more info we can look at the details and try to sort it out

[Launchpad Janitor (janitor)]

[Expired for gnome-control-center (Ubuntu) because there has been no activity for 60 days.]