The Migrator Sync Pro website will not load and displays just the web.config file with a line that says "CustomErrors=RemoteOnly"
In this case if the license file is old or outdated the site may not load.
Go directly to the database and removed all licenses lines from the table BT_licenses.
DELETE FROM TableName;
or specifically delete certain lines if you need to
DELETE FROM [BT-license]
WHERE ID = ?;
The perform an IISReset.
Try the website DirSync again for resolution.