unity-panel-service not running (no process found) at startup

[fcole90]

When I login in Trusty, I don't find any indicator (including AppMenu) in the panel.
There is no unity-panel-service active.

Running `/usr/lib/unity/unity-panel-service &` makes everything work as usual.

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: unity-services 7.2.6+14.04.20160408-0ubuntu1
ProcVersionSignature: Ubuntu 4.2.0-42.49~14.04.1-generic 4.2.8-ckt12
Uname: Linux 4.2.0-42-generic x86_64
NonfreeKernelModules: nvidia_uvm nvidia_modeset nvidia
ApportVersion: 2.14.1-0ubuntu3.21
Architecture: amd64
CompizPlugins: No value set for `/apps/compiz-1/general/screen0/options/active_plugins'
CurrentDesktop: Unity
Date: Wed Aug 3 12:05:09 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-08-02 (1 days ago)
InstallationMedia: Ubuntu 14.04.4 LTS "Trusty Tahr" - Release amd64 (20160217.1)
SourcePackage: unity
UpgradeStatus: No upgrade log present (probably fresh install)