Glade 3.38.2 usability issue (menu/title bar is all black)

I’m trying to use the Glade user interface designer. I have 3.38.2. I’m on a Mageia 8 system with a plasma-desktop-5.20.4-4.mga8. I’m not sure why, but the title/menu bar is entirely black. The only artifacts that are moderately visible are the v ^ (X) widgets in the top right along with the word “Save” in a gray color. The buttons that aren’t visible [Open], [ v ], [add page], and [hamburger] are revealed upon mouse-over, but go back to black when not moused over. There is some kind of tutorial button that is sometimes vaguely reddish, but is usually invisible.

What on earth is going on here? Where do I start to look for a way to fix this? Is there some kind of application/library that is needed by Glade that might not be set to load as a depenency of Glade?

On this same system, I am able to download an older Glade (i.e. 3.8.6) and compile it. There are no issues with its title bar, menu bar, etc. being invisible. I did not have to download any new libraries, etc., to compile it.

“It is not being actively developed or maintained anymore. If you are interested in becoming a maintainer please contact us on gitlab.”

Are you using some custom theme?

Glade 3.8 is a GTK2 application; Glade 3.38 is a GTK3 application. If you are using some custom theme that only covers GTK3, then Glade 3.8 won’t be affected.

I am not intentionally or unintentionally using a custom theme. The system is just the way it was as it was installed as per theme. I see no particular way to customize the theme for GTK 2.0 vs. 3.0, but now that you mention that, I see packages named per both gtk2 and gtk3:

greybird-gtk2-theme
greybird-gtk3-theme
vertex-dark-gtk2-theme
vertex-dark-gtk3-theme
vertex-gtk2-theme
vertex-gtk3-theme
vertex-light-gtk2-theme
vertex-light-gtk3-theme
zukitre-gtk2-theme
zukitre-gtk3-theme
zukitwo-gtk2-theme
zukitwo-gtk3-theme

Digging further in, I see these packages with theme in the name were already installed:

adwaita-gtk2-theme
greybird-gtk2-theme
greybird-gtk3-theme
gtk2-theme-engines
lib64gtk2-theme-engines
libgtk2-theme-engines
vertex-dark-gtk2-theme
vertex-dark-gtk3-theme
vertex-gtk2-theme
vertex-gtk3-theme
vertex-light-gtk2-theme
vertex-light-gtk3-theme

Some web searching shows GTK theme can be set via ~/.config/gtk-3.0/settings.ini

Mine had:

gtk-theme-name=Breeze

Packages installed with name “breeze” were:

breeze-common-5.20.4-1.mga8
lib64breezecommon5_5-5.20.4-1.mga8
breeze-5.20.4-1.mga8
breeze-gtk-5.20.4-1.mga8
breeze-icons-5.76.0-1.mga8

If I change ~/.config/gtk-3.0/settings .ini to one of the names that lists both GTK2 and GTK3 packages, i.e. greybird, then the title/menu bar issues go away and the buttons are visible. I guess this means that the default Mageia theme configuration is broken for some GTK3 applications. I tried setting various themes found in the system settings for Mageia, but none of them corrected the situation. None of greybird, vertex, vertex-light, or vertex-dark were found in the system settings GUI.

Thanks for the hint about GTK2 vs. GTK3 themes. I wonder if there is a more accessible (lol, GUI) method to set GTK theme that just isn’t installed (though I often use the shell, so I guess editing the settings.ini is not too bad for me).