Getting blank dialog boxes with apps like zenity or Document Scanner

Some updates, problems and my own doing left me with a partly functioning desktop. Applications like zenity or the Document Scanner produce a blank dialog box with only the outline (see screenshot).

When I run for example PASSWD="$(zenity --password --title Authentication)" on the command line, I get errors like:

(zenity:57813): Gtk-WARNING **: 01:51:30.718: Theme parser error: gtk.css:8086:10-13: Expected a valid color.

(zenity:57813): Gtk-WARNING **: 01:51:30.718: Theme parser error: gtk.css:8096:10-13: Expected a valid color.

(zenity:57813): Gtk-WARNING **: 01:51:30.718: Theme parser error: gtk.css:8101:10-13: Expected a valid color.

I’ve tried changing Appearance / Style as well as fonts, to no avail. Some other styles let the error messages go away, but the dialog boxes are still empty. I’ve spent much to much time trying to solve this nuisance and hope that someone can help me out.

Here the example screenshot from the Document Scanner (Simple Scan):

You could create a new user account (which will use the default values from /etc/skel) and see whether it works there.
It likely will.

You could then use that account to “reset” the original account to the same default values.

Or log out of the Xfce session
and do it from TTY

or you could kill xfsettingsd
and then do the reset from within the defunct account
and then log out and back in

pkill xfsettingsd

rm -rf ~/.cache (remove the cache folder, just for good measure)

rm -rf ~/.config/xfce4/xfconf/xfce-perchannel-xml
(remove the old and non working configuration)

cp -r /etc/skel/.config/xfce4/xfconf/xfce-perchannel-xml ~/.config/xfce4/xfconf
(copy the default configuration from /etc/skel to replace the one that you just removed)

You should end up with a fairly default and functioning desktop.

Thanks, I will try it later.

I created a new user but this fresh user had the same issues with blank dialogs.

To be clear, most dialog boxes are fine, especially the system ones. But some apps like Simple Scan or zenity give me these blank dialog boxes.

Could it be a gtk issue? How to check and what to do to install missing packages or remove conflicting ones? Of, course, the problem could be elsewhere, but the messages point in that direction.

I installed zenity-gtk3 (3.44.3-2) which solved the issue with the zenity boxes, but Simple Scan (see screen shot above) still looks the same - no text.

Ok, I removed the official Manjaro Simple Scan package and installed simple-scan-linuxmint from AUR. That works.

I have no idea why all this got messed up, but at least I found a workaround. I don’t see it as a solution, though.