Updating LibreOffice 5.3.0.3 on Ubuntu 14.04 get the seemingly regressive appearance shown below:
menubar and oldfashion icons in LibreOffice and Ubuntu
Buttons are old fashioned, there is an additional menubar, and there is no integration in Unity, the top bar only serves for displaying the name of the file, and do not have menus, as in all Unity/Ubuntu application windows.
Solutions around the menubar issue here and there do not work.