We have one large library (~10 GB) on SharePoint that cannot be synchronized with Outlook, even if you only attempt to synch one of the smaller sub folders in the library. Other libraries (or other library sub folders) work fine with Outlook.

This is with MOSS 2007 SP1 and Outlook 2007 SP2.

The error is:

Task 'SharePoint' reported error (0x80004005): 'An error occurred either in Outlook or SharePoint. Contact the SharePoint site administrator.'

Outlook Error

Reproducing the error

  1. Open up the large SharePoint document library in Internet Explorer
  2. From the Actions menu, select Connect to Outlook
  3. Select Allow on the stssync: security warning that pops up
  4. Outlook automatically tries an initial sync and sync status immediately shows the above error.

Update 1: I verified the same issue occurs on Windows XP SP3 with IE 6 using Outlook 2007 SP2 and the same SharePoint library (it was originally tested on Windows 7). The issue is definitely related to the library or Outlook.

Update 2: Using stsadm I exported the site with this large document library (8.6 GB 15,000 items) and imported it on to a development system. The result is the same on the development system - multiple clients are unable to connect Outlook to the library and get the 0x80004005 error above.

  • just for the sake of putting Outlook out of the picture, download the 2010 Beta version and test it... if it still happens, can be some setting on SharePoint – balexandre Mar 1 '10 at 14:45
  • That's an interesting idea...the 2010 beta has been on my "to do" list for a while. Another option may be to setup another 2007 server to see if it a configuration issue on our particular server. – Doug Luxem Mar 1 '10 at 14:55
  • what about this? i dont know what im doing with this ::windows8 office 2013 : Task 'sharepoint' reported error (0x80040102) : 'Outlook cannot connect to the SharePoint List (... ). The server may not be reachable from your location. Contact the SharePoint site administrator for more information. HTTP 0.' – saber tabatabaee yazdi May 22 '13 at 3:52


I have been troubleshooting this issue with Microsoft, and we have found the root cause of the error in Outlook. The error is caused by trying to synchronize folders that have two dashes ("--") in the folder name or folder path (other special characters may cause the same error.) The problem is unrelated to the size of the library or the number of items.

The fix is to rename folders that contain two or more dashes in a row. Files with two dashes are not an issue.


From other posts it looks like this could be a System.Runtime.InteropServices.COMException on your server.

For other scenarios the same error message has been fixed in a windows update. You could check that windows update has been run on your PC / SharePoint Server and Exchange Server.

Or it could simply be a bug.



  • Neither of those KB articles are applicable and all critical/security updates are applied. – Doug Luxem Feb 19 '10 at 17:43

I had also once curious troubles with Office and Sharepoint. My error was unexpected in Word.

I whould try Office Diagnostics Diagnose and repair crashing Office programs by using Office Diagnostics just to be sure there is nothing wrong with the installation.

  • The Office Diagnostics didn't find any problems, but I'm not surprised. This doesn't seem to be related to any particular client. – Doug Luxem Feb 25 '10 at 19:07

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