<A target="_blank" href="http://www-01.ibm.com/support/docview.wss?rs=463&context=SSKTMJ&context=SSPQ69&context=SSKTWP&context=SSRNU3&context=SSRNUY&dc=DB560&dc=DB520&uid=swg21406281&loc=en_US&cs=utf-8&lang=en">Technote 1406281, just published, relates to performance issues</A>, not hangs, in Domino 8.5.x. There is a hotfix, if you need it. Otherwise, the fix should be included in Domino 8.5.2.