<A target="_blank" href="http://www.vlaad.lv/lotus.nsf/dx/notes-traveler-severe-system-exception-caught-during-lotus-traveler-configuration">When Vladislav Tatarincev installed Traveler</A> on a Domino 8.5 server he got a "severe" error. It's taken him some time to track down what the problem was but he's now posted a fix.