network-manager crashes once in a while

[DasJott]

Every now and then networks stops working and I have to do

sudo service network-manager restart

for it to work again. In rare cases only a reboot helps.
The attached apport information my not contain any helpful data, as I couldn't have sent them while the error occured.

I made a cat on syslog with grep on error. This is what came along around the time of crashing:

May 18 10:25:29 jwe kernel: [56474.611316] traps: nm-applet[8390] trap int3 ip:7fcec010a9eb sp:7ffc12d93f80 error:0

May 18 10:29:10 jwe kernel: [56695.665524] audit: type=1400 audit(1463560150.577:25): apparmor="DENIED" operation="connect" info="Failed name lookup - disconnected path" error=-13 profile="/usr/lib/NetworkManager/nm-dhcp-helper" name="run/NetworkManager/private-dhcp" pid=23543 comm="nm-dhcp-helper" requested_mask="wr" denied_mask="wr" fsuid=0 ouid=0

I don't copy the whole file here, because it is full of docker logging, saying, that no external connection was possible...

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: network-manager 1.1.93-0ubuntu4
ProcVersionSignature: Ubuntu 4.4.0-22.39-generic 4.4.8
Uname: Linux 4.4.0-22-generic x86_64
ApportVersion: 2.20.1-0ubuntu2
Architecture: amd64
CurrentDesktop: Unity
Date: Wed May 18 10:52:19 2016
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2016-04-25 (22 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
IpRoute:
 default via 10.43.0.1 dev enp0s25 proto static metric 100
 10.43.0.0/16 dev enp0s25 proto kernel scope link src 10.43.1.107 metric 100
 169.254.0.0/16 dev br-886d4b6cc135 scope link metric 1000
 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
 172.18.0.0/16 dev br-886d4b6cc135 proto kernel scope link src 172.18.0.1
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=false
 WWANEnabled=true
ProcEnviron:
 LANGUAGE=de_DE
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-nm: Error: command ['nmcli', '-f', 'all', 'nm'] failed with exit code 2: Error: Object 'nm' is unknown, try 'nmcli help'.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.