nm-applet crashes if frequent disconnection-reconnection cycle occurs

[tgpraveen]

I am on ubuntu 8.10. my net connection service provider ie ISP is having some problems due to which sometimes the connection goes intoo a cycle of connection lost then reonnected and then connection lost again. this cycle occurs for a few times. till 2-3 times of this cycle nm is fine but after that the icon of NM disappears.
so last night what i did was that after it disappeared i went to terminal typed nm-applet and the icon came back and everything was fine. then i left my pc on and went to sleep. in the morning i found the terminal where i had started nm-applet had these messages and nm icon was gone again.

user@computer:~/Desktop/sify dialer$ nm-applet

** (nm-applet:21775): WARNING **: Error in getting active connection 'Vpn' property: (19) Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:21775): WARNING **: _nm_object_array_demarshal: couldn't create object for /org/freedesktop/NetworkManager/ActiveConnection/33

** (nm-applet:21775): WARNING **: _nm_object_get_property: Error getting 'ServiceName' for /org/freedesktop/NetworkManager/ActiveConnection/36: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:21775): WARNING **: _nm_object_get_property: Error getting 'Connection' for /org/freedesktop/NetworkManager/ActiveConnection/36: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

Segmentation fault

some more information. in windows xp also this cycle of disconnection-reconnection occurs but its nm does not crash.

i am on a cable net connection with a static ip address.

[Michele Mangili (mangilimic)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. Please try to obtain a backtrace following the instructions at http://wiki.ubuntu.com/DebuggingProgramCrash and upload the backtrace (as an attachment) to the bug report. This will greatly help us in tracking down your problem.

[Schuyler Erle (schuyler-nocat)]

I experienced this identical bug after upgrading from Hardy to Intrepid. Network Manager didn't segfault, but it would refuse to connect to any wireless networks. I finally fixed it by running 'apt-get remove --purge network-manager' followed by 'apt-get install network-manager-gnome'. This last step installed an additional library that hadn't been present on my system, but since I was in a hurry to get my machine working after the upgrade, I forgot to note which library that was. I hope this helps anyway.

[Milan Bouchet-Valat (nalimilan)]

Confirmed in Karmic. I've just ran into the same errors after trying to connect to a VPN (openvpn) and rebooting. I had done upgrades on 09/26 that affected NM, but my system was working after that. Anyway, reinstalling network-manager-gnome fixed it (while restarting NM and nm-applet did not), and did not install any new package on my system.

Maybe there can be a mismatch between old libnm-glib and new NM DBus API. But how can this happen after a reboot?

Updates that I had applied:
libnm-glib2 (0.8~a~git.20090911t130220.4c77fa0-0ubuntu6) to 0.8~a~git.20090923t064445.b20cef2-0ubuntu1
libnm-util1 (0.8~a~git.20090911t130220.4c77fa0-0ubuntu6) to 0.8~a~git.20090923t064445.b20cef2-0ubuntu1
network-manager (0.8~a~git.20090911t130220.4c77fa0-0ubuntu6) to 0.8~a~git.20090923t064445.b20cef2-0ubuntu1
network-manager-gnome (0.8~a~git.20090913t161448.cc2f6be-0ubuntu1) to 0.8~a~git.20090923t220421.1ac8ffd-0ubuntu4

Log:
** (nm-applet:3956): DEBUG: applet_common_device_state_changed

** (nm-applet:3956): WARNING **: _nm_object_get_property: Error getting 'State' for /org/freedesktop/NetworkManager/ActiveConnection/0: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:3956): WARNING **: _nm_object_get_property: Error getting 'Devices' for /org/freedesktop/NetworkManager/ActiveConnection/0: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:3956): WARNING **: _nm_object_get_property: Error getting 'ServiceName' for /org/freedesktop/NetworkManager/ActiveConnection/0: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:3956): CRITICAL **: applet_get_connection_for_active: assertion `scope != NM_CONNECTION_SCOPE_UNKNOWN' failed
** (nm-applet:3956): DEBUG: foo_client_state_changed_cb

[Milan Bouchet-Valat (nalimilan)]

And I should have said that the crash trace does not seem useful to me - my nm-applet does not crash either. Most probably, the original reporter got a crash in a part of the code that was not really tested because the errors should not happen. Identifying the original error is the real problem.

[unrealix (unrealix)]

I have that error when I create new wireless network and after that delete it.

** (nm-applet:8837): WARNING **: _nm_object_get_property: Error getting 'Connection' for /org/freedesktop/NetworkManager/ActiveConnection/26: Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

Segmentation fault

[Stefan Fleiter (stefan-fleiter)]

I have the same problem with karmic current as of today.
No program crash, just those 2 error messages.

** (nm-applet:4527): WARNING **: Error in getting active connection 'Vpn' property: (19) Method "Get" with signature "ss" on interface "org.freedesktop.DBus.Properties" doesn't exist

** (nm-applet:4527): WARNING **: _nm_object_array_demarshal: couldn't create object for /org/freedesktop/NetworkManager/ActiveConnection/5

[Stefan Fleiter (stefan-fleiter)]

Problem was probably caused by a defective configuration of a wireless connection.
After reinstalling everything networkmanager related and restarting network-manager by
sudo service network-manager restart I could start nm-applet, remove the connection
and create a new one.

Since then everything works smooth.