Calendar sync issue - caldavsynchronizer

Using caldav synchronizer and i am getting issues sometimes with it throwing an error, this is using nethserver and sogo.

CalDavSynchronizer. DataAccess.WebdavClientexception response status code

i have included a snip with the further details

any ideas

Any one had issues like this before?

Maybe it helps to increase the sync time range, see Outlook CalDav Synchronizer / Tickets / #6 Changing attendees in outlook leads to exception