High CPU usage of dbus-daemon for minutes after passing a path to a program to open

[Fenyvesi Attila]

I can experience very high CPU usage by dbus-daemon and delayed opening of programs like leafpad and vlc. CPU usage of dbus-daemon is 100% of a CPU core for 3 to 5 minutes if I do one of the below operations:
a) launching leafpad from thunar to open a text file (double-clicking on the file)
b) running the command "leafpad /path-to-file/file.txt"
c) launching vlc from thunar to open a video file
d) pressing Alt+F2 so as to open the Application Launcher
e) pressing Ctrl+Alt+T to open xfce4-terminal
f) opening xfce-taskmanager by clicking on the tray widget in xfce4-panel.
When I experience the above problem, a reboot can solve the problem, but sometimes the problem disappears after some time without rebooting.

I am considering upgrading from Ubuntu 16.04 to 18.04 just to eliminate this bug.
My system is up-to-date.

High CPU usage of dbus-daemon for minutes after passing a path to a program to open.

ata@HPp:~$ lsb_release -rd
Description: Ubuntu 16.04.6 LTS
Release: 16.04
ata@HPp:~$ apt-cache policy dbus
dbus:
  Telepítve: 1.10.6-1ubuntu3.4
  Jelölt: 1.10.6-1ubuntu3.4
  Verziótáblázat:
 *** 1.10.6-1ubuntu3.4 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1.10.6-1ubuntu3 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
ata@HPp:~$ apt-cache policy dbus vlc leafpad thunar
dbus:
  Telepítve: 1.10.6-1ubuntu3.4
  Jelölt: 1.10.6-1ubuntu3.4
  Verziótáblázat:
 *** 1.10.6-1ubuntu3.4 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/main amd64 Packages
        500 http://archive.ubuntu.com/ubuntu xenial-security/main amd64 Packages
        100 /var/lib/dpkg/status
     1.10.6-1ubuntu3 500
        500 http://archive.ubuntu.com/ubuntu xenial/main amd64 Packages
vlc:
  Telepítve: 2.2.2-5ubuntu0.16.04.4
  Jelölt: 2.2.2-5ubuntu0.16.04.4
  Verziótáblázat:
 *** 2.2.2-5ubuntu0.16.04.4 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages
        500 http://archive.ubuntu.com/ubuntu xenial-security/universe amd64 Packages
        100 /var/lib/dpkg/status
     2.2.2-5 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
leafpad:
  Telepítve: 0.8.18.1-4
  Jelölt: 0.8.18.1-4
  Verziótáblázat:
 *** 0.8.18.1-4 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages
        100 /var/lib/dpkg/status
thunar:
  Telepítve: 1.6.11-0ubuntu0.16.04.2
  Jelölt: 1.6.11-0ubuntu0.16.04.2
  Verziótáblázat:
 *** 1.6.11-0ubuntu0.16.04.2 500
        500 http://archive.ubuntu.com/ubuntu xenial-updates/universe amd64 Packages
        100 /var/lib/dpkg/status
     1.6.10-2ubuntu1+patch1 500
        500 http://ppa.launchpad.net/yuri-sucupira/thunar1.6.10-fix/ubuntu xenial/main amd64 Packages
     1.6.10-2ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu xenial/universe amd64 Packages