OneDrive for Business sync returns the error "We can't connect to the specified SharePoint site"
When you click Sync Now in Microsoft SharePoint or OneDrive for Business, the following error is returned:
We can't connect to the specified SharePoint site
This issue occurs if one of the following registry values is configured as follows:
SignInOptions=3 restricts you from signing in to SharePoint or SharePoint Online by using either a Microsoft or an organizational ID.
The x.0 placeholder represents your Office version (16.0 = Office 2016, Office 2019, Office LTSC 2021, or Microsoft 365 Apps, 15.0 = Office 2013).
Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you modify it, back up the registry for restoration in case problems occur.
To resolve this issue, follow these steps:
Click OK to close the sync window.
Start Registry Editor.
Locate and select the following subkey:
Double-click the SignInOptions value.
In the Value Data box, type 0, and then click OK.
Exit Registry Editor.
If the SignInOptions value is located under the Policies hive, it may have been created by Group Policy. In this situation, your administrator must modify the policy to change this setting.
The SignInOptions value controls whether users can provide credentials to Office by using either their Microsoft Account ID or the user ID that was assigned by their organization (Org ID) for accessing Microsoft 365. This setting can be configured by using the following values:
- 0 = Both ID types allowed
- 1 = Only Microsoft Account IDs allowed
- 2 = Only Org IDs allowed
- 3 = Users can't sign in by using either type of ID