Comment 11 for bug 1773945

From the cells v2 meeting today about the nova side of this bug (comment 9):

(12:02:39 PM) dansmith: yeah, I think it's legit to log an error if the mapping is null so that the operator can fix it up
(12:02:46 PM) mriedem: and raise 500
(12:02:48 PM) mriedem: ?
(12:02:49 PM) dansmith: yeah
(12:02:50 PM) mriedem: ok
(12:02:58 PM) dansmith: because it's legit internal "we screwed up" error