Created attachment 122994 [details] The menu, and underlined the lists that can not be selected Libre Office has been install with an odd icon style, which is hardly visible in my desktop. But in the option/display menu, It is not possible to change the icon style. The list of available set is correctly displayed, but they can not be selected. On the left, the automatic/small/large menu is also available but not selectable.
Fixed for 5.1.1. In the meantime use the gtk2 backend. (Under Ubuntu remove the libreoffice-gtk3 package, and make sure you have libreoffice-gtk.) *** This bug has been marked as a duplicate of bug 96604 ***