Recently my iCal subscriptions (to a VRBO calendar) stopped syncing in my Zimbra client. When I try to resubscribe to the ical via URL I get, "The Following URL is not currently reachable" error. This same url and subscription works in google calendar and a couple other places, but not the Zimbra clients (I tried two different ones).
It may be that there is some data in my calendar that is corrupt?
and ideas?