I installed Lubuntu 16.04 on an Acer Extensa 2511, 64-bit (then I installed ubuntu-mate-desktop and ubuntu-mate-core). With both lubuntu and MATE, Libreoffice WRITER crashes often, shutting the desktop session down and bringing me back to the login window. I tried to reinstall libreoffice; to remove libreoffice and MATE and to install MATE again,; to reinstall jre. None of these worked. I dont’t think the problem is MATE rather than Lubuntu/lxde, this happened with lubuntu as well before installing MATE the fist time. Libreoffice version is 5.1.
Have you tried to call Writer from the terminal? There are several crashes that could be investigated this way. It suppose to write down the errors…