After activating JDK 8u102 in LibreOffice --> Advanced --> Java Options the Writer application freezes / hangs and the beachball appears when pressing the menu bar at the top. Only a forced quit can close the application. JDK 8u92 does not have this issue. Reverting from u102 to u92 fixes the issue. Without activating JDK u102 Writer crashes often after launching it.
Which LibreOffice version are you using? If not 5.1.5 or 5.2.0, please upgrade to either of those.
*** This bug has been marked as a duplicate of bug 101057 ***