Ical unexpected network error 60 when restoring

Question

When trying to restore a 19.8 MB backup file to iCal, I get an "unexpected network error 60".  What does the error mean?

Answer 1

Turns out, I think, that an error 60 means "communication stopped."  This occurs if a backup file is being imported (restored) and any significant change has occurred to the caldav server.  When backing up a calendar it must be performed by individual calendar to be able to import it onto a new server.  This may seem like it would take longer, but trust me, it is the way to make it work.
For information, the backup is a "bundle", (file extension ".icbu") and inside the bundle are various files and plist (parameter list) files that contain various information so that things can be restored exactly the way they were when they were backed up.  The plist files include the server URLs.  Although it is feasible to edit the plist files, it is not trivial.
So when an import/restore is performed from an ".icbu" file, synchonization is lost as the new plists are read in.
An ".ics" file extension is an ICal save file, and has only one mail box in it.  It can be loaded into a different server with ease, as when it is imported iCal asks which mail box to put it in.  The mailbox must already be created.
Make certain to provide time for the spinning wheel to stop after importing before you start doing any other activity on iCal.  It might seem like iCal is multi-tasking, but at least the OS X 10.6.8 version is not!  If you interrupt the server synchonization process, either the spinner will never stop or you will get an error (exclamation mark).  I have found that quitting iCAL and then restarting it will usually get things going again.  However, give it time and you shouldn't have any problems.
And if you search for iCal error 60 you will find a lot of questions but few if any answers.  I hope this discussion helped and will save you from my many hours investment.