The request failed. The remote server returned an error: (401) Unauthorized.

Problem

During a migration to or from Exchange or Office 365, you’re getting the following error:

Fatal error during migration process: The request failed. The remote server returned an error: (401) Unauthorized.

Cause 1: during mail migration

Most probably, the usersname and passwords entered in the connector are incorrect.

Resolution

Connect to http://portal.office.com and try to login with the administrator and password account defined in the connector.
If it doesn’t work, correct the credentials.

 

Cause 2: during site migration – credentials

The administrator and password entered in the source or target connector do not have enough permissions to access the particular SharePoint site collection you want to access.

Resolution

Connect to SharePoint central administration (eg: https://company-admin.sharepoint.com) and select the site collection. Then click on Owners -> Manage Administrators : Add your administrator in the field Site Collection Administrators.

 

Cause 3: during site migration – collection creation

The target site collection is not created in the SharePoint central administration.
Please note : the site collection must be created prior the site migration.

Resolution

Create the SharePoint site collection in the SharePoint central administration following these steps:

– Connect to SharePoint central administration (eg: https://company-admin.sharepoint.com)

– Under site collections, click on New -> Private Site Collection. Here you can create your site collection.

Once the site is created, you can relaunch the site migration using the newly-created site settings and information.