Plank not displayed

[Axel Moulin]

Hello !
I'm using Plank on Linux Mint and the process appears, but nothing is displayed. I mean, the dock is not appearing but the process runs in background. I tried to download Docky to test, and same, the process is running, but nothing is displayed. With Plank (which was configured to hide automatically), I can see that the process is demanding more resources when i put my mouse's pointer at the bottom of the screen (like if it wants to be displayed). It worked fine yesterday but not today. I also tried to reboot my computer, nothing more happened. I ran the "plank -d" command and I found this :

[DEBUG 13:05:13.370704] [Gtk] Connecting to session manager
[INFO 13:05:13.371534] [AbstractMain:229] Plank version: 0.11.4.24-0a84
[INFO 13:05:13.371562] [AbstractMain:230] Kernel version: 4.10.0-38-generic
[INFO 13:05:13.371582] [AbstractMain:231] GLib version: 2.48.2 (2.48.2)
[INFO 13:05:13.371605] [AbstractMain:234] GTK+ version: 3.18.9 (3.18.9)
[INFO 13:05:13.371624] [AbstractMain:237] Wnck version: 3.14.1
[INFO 13:05:13.371648] [AbstractMain:238] Cairo version: 1.14.6
[INFO 13:05:13.371666] [AbstractMain:239] Pango version: 1.38.1
[INFO 13:05:13.371685] [AbstractMain:241] + Cairo/Gtk+ HiDPI support enabled
[INFO 13:05:13.371704] [AbstractMain:244] + Dynamic Quicklists support enabled
[INFO 13:05:13.371723] [AbstractMain:247] + XInput Barriers support enabled
[INFO 13:05:13.390631] [WindowControl:68] Window-manager: KWin
[DEBUG 13:05:13.391649] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-applications.so'
[INFO 13:05:13.391695] [DockletManager:107] Docklet 'applications' registered
[DEBUG 13:05:13.392220] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-desktop.so'
[INFO 13:05:13.392258] [DockletManager:107] Docklet 'desktop' registered
[DEBUG 13:05:13.392779] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-clippy.so'
[INFO 13:05:13.392817] [DockletManager:107] Docklet 'clippy' registered
[DEBUG 13:05:13.393353] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-trash.so'
[INFO 13:05:13.393391] [DockletManager:107] Docklet 'trash' registered
[DEBUG 13:05:13.393910] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-cpumonitor.so'
[INFO 13:05:13.393948] [DockletManager:107] Docklet 'cpumonitor' registered
[DEBUG 13:05:13.394517] [DockletManager:204] Loading module '/usr/lib/x86_64-linux-gnu/plank/docklets/libdocklet-clock.so'
[INFO 13:05:13.394556] [DockletManager:107] Docklet 'clock' registered
[INFO 13:05:13.394851] [AbstractMain:301] Running with 1 docks ('dock1')
[DEBUG 13:05:13.394913] [DockController:80] Create dock 'dock1' (config_folder = /home/axel/.config/plank/dock1)
[DEBUG 13:05:13.395034] [Settings:53] Bind 'PlankDockPreferences' to '/net/launchpad/plank/docks/dock1/'
[DEBUG 13:05:13.433060] [Preferences:349] Loading preferences from file '/home/axel/.local/share/plank/themes/Dark-MAC THEME(SQUARE) 3.1/dock.theme'
[DEBUG 13:05:13.434199] [ItemFactory:176] Loading dock elements from '/home/axel/.config/plank/dock1/launchers'
[DEBUG 13:05:13.434551] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/firefox.dockitem'
[DEBUG 13:05:13.435094] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/systemsettings.dockitem'
[DEBUG 13:05:13.435520] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/desktop.dockitem'
[DEBUG 13:05:13.437219] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/trash.dockitem'
[DEBUG 13:05:13.441209] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/org.kde.konsole.dockitem'
[DEBUG 13:05:13.441716] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/mintinstall.dockitem'
[DEBUG 13:05:13.442174] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/org.kde.dolphin.dockitem'
[DEBUG 13:05:13.442566] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/spotify.dockitem'
[DEBUG 13:05:13.442934] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/com.discordapp.Discord.dockitem'
[DEBUG 13:05:13.443309] [Preferences:349] Loading preferences from file '/home/axel/.config/plank/dock1/launchers/messengerfordesktop.dockitem'
[DEBUG 13:05:13.471810] [Unity:164] Initializing LauncherEntry support
[INFO 13:05:13.472146] [HideManager:618] Barriers enabled (XInput 2.3 support)
[DEBUG 13:05:13.472205] [PositionManager:677] Without draw_values there is trouble ahead
[DEBUG 13:05:13.476920] [Unity:133] com.canonical.Unity acquired
[INFO 13:05:13.536354] [DockRenderer:491] Cairo.SurfaceType: XLIB
[WARN 13:05:13.557922] [LIBDBUSMENU-GLIB] Unable to get session bus: L’opération a été annulée
[WARN 13:05:13.560925] [LIBDBUSMENU-GLIB] Unable to get session bus: L’opération a été annulée
[WARN 13:05:13.563910] [LIBDBUSMENU-GLIB] Unable to get session bus: L’opération a été annulée

I'm french so "L'opération a été annulée" means "Operation cancelled". I tried to copy-paste the "WARN" line in web but all i can find is to do "sudo apt-get install dbus-x11" but it shows me that this is already installed.

Can you help me ?
Thanks !

---Other informations---

Plank's version : 0.11.4.24-0a84
Linux distro : Linux Mint 18.3 Silvia with KDE environment
By typing "gdb --args plank -d" :

GNU gdb (Ubuntu 7.11.1-0ubuntu1~16.5) 7.11.1
Copyright (C) 2016 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<http://www.gnu.org/software/gdb/documentation/>.
For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from plank...(no debugging symbols found)...done.

My video card is an Nvidia MX150 but I a newbie on linux so I don't know how to see the driver's version.
Desktop environment : KDE
Installation of Plank : By command-lines :

    - adding the "ppa:docky-core/stable"
    - typing : "sudo apt-get update"
    - typing : "sudo apt-get install plank"

[Axel Moulin (hycebeerg)]

I found that my screen wasn't using the good render motor, so it cannot be displayed. I changed this and Plank was appearing by magic.

[Axel Moulin (hycebeerg)]

Use XRender motor.