Comment 15 for bug 1625595

found a work around. I removed libreoffice-kde and install libreoffice-gtk (which will also install libreoffice-gtk2). Launch libreoffice as normal and the icons and menus are working properly. I then uninstalled libreoffice-gtk and libreoffice-gtk2 and reinstalled libreoffice-kde which reproduced the problem in this bug report. Seems only libreoffice-kde is at fault.

hope this helps and let me know if i can try anything else.