Is this missing dependency-bug of Python3 in Kazam of Debian 8.5?

I tried to record the bug related to my typing but could not get Kazam work as root and as non-root, see following; I installed it by apt-get install kazam ffmpeg successfully but not properly because of the errors/warnings root@masi:/home/masi# kazam Traceback (most recent call last): File "/usr/bin/kazam", line 127, in bus = dbus.SessionBus() File "/usr/lib/python3/dist-packages/dbus/_dbus.py", line 211, in __new__ mainloop=mainloop) File "/usr/lib/python3/dist-packages/dbus/_dbus.py", line 100, in __new__ bus = BusConnection.__new__(subclass, bus_type, mainloop=mainloop) File "/usr/lib/python3/dist-packages/dbus/bus.py", line 122, in __new__ bus = cls._new_for_bus(address_or_type, mainloop=mainloop) dbus.exceptions.DBusException: org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken. root@masi:/home/masi# exit exit masi@masi:~$ kazam /usr/lib/python3/dist-packages/kazam/app.py:145: Warning: value "((GtkIconSize) 32)" of type 'GtkIconSize' is invalid or out of range for property 'icon-size' of type 'GtkIconSize' self.builder.add_from_file(os.path.join(prefs.datadir, "ui", "kazam.ui")) (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-screencast-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-screenshot-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Can't set a parent on widget which has a parent (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-fullscreen-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-all-screens-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-window-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Symbolic icon kazam-area-symbolic of size 24 is in an icon theme directory of size 16 (kazam:5260): Gtk-WARNING **: Can't set a parent on widget which has a parent I did as root apt-get update and apt-get upgrade after that and iterated again but the problem persists. Debugging --- I run kazam --debug and get masi@masi:~$ kazam --debug DEBUG Kazam - Starting ... DEBUG Kazam - Running on: debian 8.5 DEBUG Kazam - Kazam version: 1.4.5 NCC-80102 DEBUG Kazam - Starting new instance ... DEBUG Prefs - XDG_PICTURES is a directory and accessible DEBUG Prefs-HW - Getting hardware specs DEBUG Prefs-HW - Getting Video sources. DEBUG Prefs-HW - Found 1 monitor(s). DEBUG Prefs-HW - Monitor 0 - X: 0, Y: 0, W: 1920, H: 1080 DEBUG Main - Gstreamer version detected: 1.4.4.0 DEBUG Main - Setting variables. DEBUG PulseAudio - Starting mainloop. DEBUG PulseAudio - Getting API. DEBUG PulseAudio - Setting context. DEBUG PulseAudio - Set state callback. DEBUG PulseAudio - Connecting to server. DEBUG PulseAudio - Start mainloop. DEBUG PulseAudio - State connected. DEBUG Main - Connecting indicator signals. DEBUG Main - Starting in silent mode: False DEBUG Indicator - Indicatior silent: False DEBUG Indicator - Trying to bind hotkeys. DEBUG Main - Main Window UI setup. /usr/lib/python3/dist-packages/kazam/app.py:145: Warning: value "((GtkIconSize) 32)" of type 'GtkIconSize' is invalid or out of range for property 'icon-size' of type 'GtkIconSize' self.builder.add_from_file(os.path.join(prefs.datadir, "ui", "kazam.ui")) DEBUG Main - Unable to get name for '' (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-screencast-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-screenshot-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Can't set a parent on widget which has a parent (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-fullscreen-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-all-screens-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-window-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Symbolic icon kazam-area-symbolic of size 24 is in an icon theme directory of size 16 (kazam:3222): Gtk-WARNING **: Can't set a parent on widget which has a parent DEBUG Prefs - Getting Audio sources. DEBUG PulseAudio - get_audio_sources() called. DEBUG PulseAudio - pa_sourcelist_cb() DEBUG PulseAudio - IDX: 0 DEBUG PulseAudio - Name: b'alsa_output.pci-0000_00_1f.3.analog-stereo.monitor' DEBUG PulseAudio - Desc: b'Monitor of Built-in Audio Analog Stereo' DEBUG PulseAudio - pa_sourcelist_cb() DEBUG PulseAudio - IDX: 1 DEBUG PulseAudio - Name: b'alsa_input.pci-0000_00_1f.3.analog-stereo' DEBUG PulseAudio - Desc: b'Built-in Audio Analog Stereo' DEBUG PulseAudio - pa_sourcelist_cb() -- finished DEBUG Prefs - Device found: DEBUG Prefs - - 0 DEBUG Prefs - - alsa_output.pci-0000_00_1f.3.analog-stereo.monitor DEBUG Prefs - - Monitor of Built-in Audio Analog Stereo DEBUG Prefs - Device found: DEBUG Prefs - - 1 DEBUG Prefs - - alsa_input.pci-0000_00_1f.3.analog-stereo DEBUG Prefs - - Built-in Audio Analog Stereo DEBUG Main - Capture cursor: True. DEBUG Main - Capture cursor_pic: True. DEBUG Main - Capture borders_pic: True. Testing GAD3R's proposal --- I run apt-get build-dep kazam successfully, then again kazam but get the similar warnings/errors still /usr/lib/python3/dist-packages/kazam/app.py:145: Warning: value "((GtkIconSize) 32)" of type 'GtkIconSize' is invalid or out of range for property 'icon-size' of type 'GtkIconSize' self.builder.add_from_file(os.path.join(prefs.datadir, "ui", "kazam.ui")) (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-screencast-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-screenshot-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Can't set a parent on widget which has a parent (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-fullscreen-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-all-screens-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-window-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Symbolic icon kazam-area-symbolic of size 24 is in an icon theme directory of size 16 (kazam:15470): Gtk-WARNING **: Can't set a parent on widget which has a parent I think this may be the problem that Kazam wants python3 but I have python 2.7.9 (python --version gives Python 2.7.9), so there can be a missing dependency. How to proceed? Hardware: Asus Zenbook UX303UA OS: Debian 8.5 Linux kernel: 4.6 (backports' one) Graphics: modesetting and non-free package for skylake CPU support Case in Kazam suppot: https://answers.launchpad.net/kazam/+question/378875