Strange bug. I launch 5.1.1.3 on Windows (7x64)... For example LibreOffice Write. It opens. I click on File->Exit LibreOffice ... NOTHING HAPPENS. If I click on the red cross top right corner of the window, it properly closes it. If I use the "Ctrl-Q" shortcut, it properly closes it. Just the file->Exit LibreOffice menu doesn't. Same behavior on all other apps (Calc, Impress...) Doesn't happen on Ubuntu Linux... here closing method works. Do you get that behavior too?
*** This bug has been marked as a duplicate of bug 92516 ***