It's still unresolved. In my case this happens when I have installed and activated the theme "PRO-Dark-XFCE-Edition 4.14" ( https://www.xfce-look.org/p/1207818/ )
It's still unresolved. In my case this happens when I have installed and activated the theme "PRO-Dark- XFCE-Edition 4.14" ( https:/ /www.xfce- look.org/ p/1207818/ )