Network connections drop for no reason and have to restart manually to work again

[fw114]

DHCP Network connection

eth0 card drops connection and is not av. anymore.

you have to choose disconnect and reconnect manually

ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: network-manager 1.0.4-0ubuntu5.3
ProcVersionSignature: Ubuntu 4.2.0-35.40-generic 4.2.8-ckt5
Uname: Linux 4.2.0-35-generic x86_64
NonfreeKernelModules: nvidia
ApportVersion: 2.19.1-0ubuntu5
Architecture: amd64
Date: Tue Apr 5 14:50:28 2016
IfupdownConfig:
 # interfaces(5) file used by ifup(8) and ifdown(8)
 auto lo
 iface lo inet loopback
InstallationDate: Installed on 2016-01-07 (88 days ago)
InstallationMedia: Kubuntu 15.10 "Wily Werewolf" - Release amd64 (20151021)
IpRoute:
 default via 192.168.0.1 dev enp2s0 proto static metric 100
 169.254.0.0/16 dev enp2s0 scope link metric 1000
 192.168.0.0/24 dev enp2s0 proto kernel scope link src 192.168.0.31 metric 100
IwConfig:
 enp2s0 no wireless extensions.

 lo no wireless extensions.
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
 WimaxEnabled=true
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
RfKill:

SourcePackage: network-manager
UpgradeStatus: No upgrade log present (probably fresh install)
nmcli-con:
 NAME UUID TYPE TIMESTAMP TIMESTAMP-REAL AUTOCONNECT AUTOCONNECT-PRIORITY READONLY DBUS-PATH ACTIVE DEVICE STATE ACTIVE-PATH
 Kabelnetzwerkverbindung 1 3c8dcb3c-23b7-4a64-a4aa-9dc20504a0e6 802-3-ethernet 1459860635 Di 05 Apr 2016 14:50:35 CEST yes 0 no /org/freedesktop/NetworkManager/Settings/0 yes enp2s0 activated /org/freedesktop/NetworkManager/ActiveConnection/0
nmcli-dev:
 DEVICE TYPE STATE DBUS-PATH CONNECTION CON-UUID CON-PATH
 enp2s0 ethernet connected /org/freedesktop/NetworkManager/Devices/1 Kabelnetzwerkverbindung 1 3c8dcb3c-23b7-4a64-a4aa-9dc20504a0e6 /org/freedesktop/NetworkManager/ActiveConnection/0
 lo loopback unmanaged /org/freedesktop/NetworkManager/Devices/0 -- -- --
nmcli-nm: Error: command ['nmcli', '-f', 'all', 'nm'] failed with exit code 2: Error: Object 'nm' is unknown, try 'nmcli help'.