try this...
Before you try to migrate content, verify that the account on the server you're migrating from is a "sudo" account. Otherwise, you will get an error like this one when you try to migrate:
Cannot send scout to the remote host
Failed to execute scout.
-To Add an Account to the "sudo" File on a Plesk Server
In your browser, log in to Plesk (on your previous server) and verify that the user you want to use to transfer content has SSH access.
-Log in to your server using SSH. At the command line, type su and use the password for the primary user ID on your server.
-Once you have root access, type visudo to open the sudo file you need to edit. NOTE: Do not edit this file using the standard vi editor. Use visudo instead.
-In the User Privilege section, add the following line, where "USER" is the user ID you created in Plesk: USER ALL=(ALL) ALL
-Type :wq to close visudo.
-After you add your account to the sudo file on the server you are transferring content from, you can connect to your new server and use the Migration Manager to transfer your content.