Theme parsing errors on Kubuntu 18.04

[andrearuggirello]

After upgrading to Kubuntu 18.04 from 16.04.5 LTS I get the following messages running a zenity dialog:

(zenity:30525): Gtk-WARNING **: 10:08:11.591: Theme parsing error: gtk.css:68:35: The style property GtkButton:child-displacement-x is deprecated and shouldn't be used anymore. It will be removed in a future version (zenity:30525): Gtk-WARNING **: 10:08:11.591: Theme parsing error: gtk.css:69:35: The style property GtkButton:child-displacement-y is deprecated and shouldn't be used anymore. It will be removed in a future version (zenity:30525): Gtk-WARNING **: 10:08:11.591: Theme parsing error: gtk.css:70:34: The style property GtkCheckButton:indicator-size is deprecated and shouldn't be used anymore. It will be removed in a future version (zenity:30525): Gtk-WARNING **: 10:08:11.591: Theme parsing error: gtk.css:73:46: The style property GtkScrolledWindow:scrollbars-within-bevel is deprecated and shouldn't be used anymore. It will be removed in a future version Gtk-Message: 10:08:11.666: GtkDialog mapped without a transient parent. This is discouraged.

I don't think this is in any way related to the KDE Plasma desktop though; looks like a number of deprecations resulting from a Gtk version bump.

Thanks and keep up the good work!

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Yuri Gor (yuri-horus)]

I also see this when start Chrome/Chromium in the Kubuntu 18.04