First off when posting a problem we have guidelines to help you help us. Please read and follow this thread here: please-read-before-requesting-assistanceSorry, I have no idea what your talking about. I do not recall ever seeing a "Calendar View for Tickets" mod ever. If this is something that you installed via instructions from this forum please provide a link to the mod. If this was a mod written for an older version you will need to contact the author of the mod to get them to update it or update it yourself. Mods written for 1.6 or 1.7 will likely not function on 1.8.