There is a fix for this: https://ubuntuforums.org/showthread.php?t=2305819
add a file to the /etc/modules-load.d directory to have the modules loaded into the kernel at boot. I just created a file called netfilter.conf and put the following in it: nf_nat_pptp nf_conntrack_pptp nf_conntrack_proto_gre Is it safe to use this solution? I don't know what those three entries mean. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to network-manager in Ubuntu. https://bugs.launchpad.net/bugs/1568560 Title: nm_device_get_device_type: assertion 'NM_IS_DEVICE (self)' failed Status in NetworkManager: New Status in network-manager package in Ubuntu: Confirmed Bug description: Hello, On Ubuntu 15.10 4.2.0-35, with network-manager 1.0.4-0ubuntu5.3 My WiFi connection is very unstable and I have to often restart NetworkManager service (~ a dozen times every day...): sudo systemctl -l status NetworkManager ● NetworkManager.service - Network Manager Loaded: loaded (/lib/systemd/system/NetworkManager.service; enabled; vendor preset: enabled) Active: active (running) since dim. 2016-04-10 18:17:07 CEST; 2min 58s ago Main PID: 27832 (NetworkManager) Memory: 13.8M CPU: 1.729s CGroup: /system.slice/NetworkManager.service ├─ 2703 /usr/sbin/dnsmasq --no-resolv --keep-in-foreground --no-hosts --bind-interfaces --pid-file=/run/sendsigs.omit.d/network-manager.dnsmasq.pid --listen-address=127.0.1.1 --conf-file=/var/run/NetworkManager/dnsmasq.conf --cache-size=0 --proxy-dnssec --enable-dbus=org.freedesktop.NetworkManager.dnsmasq --conf-dir=/etc/NetworkManager/dnsmasq.d ├─27832 /usr/sbin/NetworkManager --no-daemon └─30448 /sbin/dhclient -d -q -sf /usr/lib/NetworkManager/nm-dhcp-helper -pf /run/sendsigs.omit.d/network-manager.dhclient-wlan0.pid -lf /var/lib/NetworkManager/dhclient-7ec429cb-9dde-4ea4-8eda-f259b66e38a7-wlan0.lease -cf /var/lib/NetworkManager/dhclient-wlan0.conf wlan0 avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> keyfile: add connection in-memory (068de9b1-513a-46f0-b4be-93462d19f68b,"lxcbr0") avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (lxcbr0): device state change: unmanaged -> unavailable (reason 'connection-assumed') [10 20 41] avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (lxcbr0): device state change: unavailable -> disconnected (reason 'connection-assumed') [20 30 41] avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (lxcbr0): Activation: starting connection 'lxcbr0' (068de9b1-513a-46f0-b4be-93462d19f68b) avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (virbr1-nic): new Tun device (carrier: OFF, driver: 'tun', ifindex: 34) avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (virbr1): bridge port virbr1-nic was attached avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (virbr1-nic): enslaved to virbr1 avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <info> (virbr0): new Bridge device (carrier: OFF, driver: 'bridge', ifindex: 29) avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: nm_device_get_device_type: assertion 'NM_IS_DEVICE (self)' failed avril 10 18:17:08 samsung-ubuntu NetworkManager[27832]: <warn> failed to enumerate oFono devices: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.ofono was not provided by any .service files Also, each time I restart my desktop, NetworkManager generates a crash report: cf. attached screenshots. I have tried an Ubuntu VM with the same packages related to networking and the exact same releases (same repositories), the crash never happens; the difference appears to be only the type of network connection: WiFi for the desktop vs Ethernet for the VM. Any suggestion? To manage notifications about this bug go to: https://bugs.launchpad.net/network-manager/+bug/1568560/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp