"The request failed with HTTP status 401: Unauthorized" when copying site from SharePoint 2013 (4322083)

The error message below is encountered when migrating workflows from a read-only site collection in a SharePoint 2013 On-Premises environment that is configured with the SharePoint Designer 2013 Platform workflow:

Exception: The request failed with HTTP status 401: Unauthorized.

Error: The request failed with HTTP status 401: Unauthorized.
Stack: at Metalogix.SharePoint.Adapters.MLWS.MLWSAdapter.ExecuteMethod(String sMethodName, Object[] parameters)
   at Metalogix.SharePoint.Adapters.MLWS.MLWSAdapter.GetSP2013Workflows(String configurationXml)
   at Metalogix.SharePoint.Workflow2013.SP2013WorkflowCollection.GetSP2013Workflows(String configurationXml)
   at Metalogix.SharePoint.Actions.Migration.PasteListAction.CopyList(SPList sourceList, SPWeb targetWeb, Boolean bIsCopyRoot, Boolean bDisablePermissions, Boolean bCopyingForDependency)

Type: System.Net.WebException

• This is a reported issue and support is currently working on identifying the cause and the permanent fix to resolve it.
• It is caused when the source site collection is in a Read Only state.

Please perform the steps below as a workaround:

1. Open Central Administration of the source environment.
2. Go to Application Management > Site Collections > Configure quotas and locks.
3. Select the source site collection and enable "Adding content prevented" on the Site Lock Information section.
   
   
    
4. Refresh the source connection on the Content Matrix Console, and run the migration again.