As above, if I click on File > Templates > Manage, for some bizarre reason LibreOffice 5.1 will open the Navigation Toolbar. That is under my current configuration; with a clean install and a fresh user profile, it will just as bizarrely open the Form Design toolbar. If I want to access the template manager, I have to use the keyboard shortcut Shift+Ctrl+N; I can’t get at it through mouse-clicking.