Outlook errors connecting to a SharePoint Document Library

Last Updated: March 26, 2020

ISSUE

After a recent change Outlook will error when connecting to a SharePoint Document Library.

This dialog appears when you select Connect to Outlook from a SharePoint list or Document Library.

Connect to a SharePoint Document Library

After you select Yes to the dialog above you see this error:

"Task 'SharePoint' reported error (0x80004005): 'The operation failed.'"

Error connecting to a SharePoint Document Library

SharePoint stssync error

Note: The errors above will also happen if you choose Update Folder for a Document Library already connected in Outlook SharePoint Lists.

STATUS: WORKAROUND

This issue occurred after a recent change to deprecate the "Edit Offline" functionality for SharePoint documents synced to Outlook. Per the guidance about that change, it is recommended that you sync SharePoint libraries to your computer using OneDrive.

Longer term the Outlook feature to connect to a SharePoint document library will be deprecated. In the meantime if you need to use the feature while you migrate your documents to OneDrive you can set a registry key to address the issue.

Important: This task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs.

HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Offline\Options
DWORD: CheckoutToDraftsEnabled
Value data: 1

In Windows, right-click Start, and then select Run. In the Open: box type regedit, and then choose OK. This will open the registry editor.
Find this subkey in the registry and then click it:
- HKEY_CURRENT_USER\Software\Microsoft\Office\Common\Offline\Options
Select the Options key.
Click Edit > New > DWORD Value.
Type CheckoutToDraftsEnabled for the name of the DWORD, and then press Enter.
Right-click CheckoutToDraftsEnabled, and then click Modify.
In the Value data box, type 1 to enable the registry entry, and then click OK.
Exit Registry Editor, and then restart Outlook.