I have recently updated my laptop from Office 2010 to Office 2013 (locally, i.e. without Exchange server, Win 8.1 64 bit) and now I’m experiencing a very annoying problem:

When I put my calendar online (using the "Publish to WebDAV Server") all appointments in my local calendar are deleted upon a restart of Outlook. I have been able to reproduce this a couple of times.

The online publication process itself is working. I can see the .ics file that has been created on the WebDAV server, I can open it from another computer’s Outlook and all the appointments are still in there. On my laptop however, the calendar contents are lost irreversibly, as evidenced by the sudden and dramatic decrease of the size of the PST file when Outlook is restarted.

The whole process does not generate any errors. The only message related to this occurs when Outlook tries to sync the calendar at a later time, leading to “Calendar Sharing Error 0x8004010F ".

I am using a freehoster as a WebDAV server for the calendar sharing, the name of which is irrelevant. I know that the problem is not caused by anything on the server side. On my desktop computer I have exactly the same setup (identical OS and Office) and this computer shares its calendar fine on the same server. I can even open the shared calendar on my laptop and everything is OK. It’s just that on my laptop this particular sharing process fails. So I guess it has something to do with my PST file and with something that Outlook does upon publishing the data.

I can restore a previously backed up PST file no problem, which also restores the Calendar contents and the above mentioned error also disappears. Until I try again to publish the calendar ...

Any idea what I can do about this??