The case page name, in the format {{medcabbox|CASE PAGE NAME}} has either been removed from the template or this template has been placed on a page using {{medcab-request}} instead of {{subst:medcab-request}}. This template will not function until you add the case page name again, if you need help with this, try contacting the Mediation Cabal.
Note: the second parameter defaults to open, so no need to supply. Use "closed" to change the message so the case can be put on the talk page for archival purposes. Probably best to pass |small=yes as well to avoid clutter if you're marking closed. Or just remove altogether if the dispute is finished.
