I've installed Kubuntu 18.04 LTS twice with the same results. After installing compiz first all my toolbars disappear.

Then I go into CCSM>preferences and change the Backend drop down to GSettings Configuration Backend.
The toolbars reappear after I enable GSettings Configuration Backend and check the box for Wobbly Windows by default enables Windows Decoration.
After I've done that the toolbars return but are all white and without decoration.

I noticed that if I run this windows decoration command with --replace, I get this:

liveevil@liveevil-P5E3-Deluxe:~$ /usr/bin/gtk-window-decorator



** (gtk-window-decorator:32130): WARNING **: 08:35:56.021: Failed to load metacity theme 'Adwaita': Failed to find a valid file for theme 'Adwaita'

Any help would be greatly appreciated...

screenshot