Volume exclusive access is required to complete the operation

Using Migrate OS to SSD 5.0 ver. 10.1.28.154 to clone a 500gb platter drive on a new Dell Latitude 5580 to a 500gb Samsung 850 EVO. The OS on the notebook is Win 10 Pro 10.0.15063 Build 15063. After repeated attempts get the following message: Volume exclusive access is required to complete the operation. What would you like to do? The operation Selective copy disk needs exclusive access to the volume C: and cannot be completed. Please retry or cancel the operation.

There is a link for "What files prevent operation completion?" This link returns an empty list of files.

Same results whether Secure Boot is enabled or disabled.

What's necessary to get this cloning process to complete?

Thanks

Jay