I've installed the latest Debian calendarserver package on Ubuntu 14.04 on 3 different more-or-less identical Dell servers. On one of the 3 servers I am experiencing an error. It started when I imported calendar events from a particularly large calendar. The symptom on the client side is a "CalDAVAccountRefreshQueueableOperation" error. It occurs now with every attempt to connect to the account. The symptom on the server side is: 2015-11-13 09:21:33-0700 [-] [caldav-0] File "/usr/lib/python2.7/dist-packages/txdav/common/datastore/sql.py", line 1570, in initFromStore 2015-11-13 09:21:33-0700 [-] [caldav-0] self._txn, resourceID=self._resourceID))[0] 2015-11-13 09:21:33-0700 [-] [caldav-0] exceptions.IndexError: list index out of range Thinking this to perhaps be due to corrupt data, I deleted the caldav database plus files in the /var/spool/caldavd and /var/lib/caldavd, restarted the server and am still getting that error each time I try to connect. The error seems to be from Python and has come up for users of other packages too. If it isn't the calendar data that is causing or contributing to this error, is there a Python cache or other persistent data that needs to be deleted to really have a fresh start with calendarserver? Because my other two installs are working fine, including one where I imported the same data. Any clues? ./k