An error has occurred during the restore operation because a user owns objects in the database. All objects should be owned by dbo and not by a specific user.
Ensure that all objects in the database are owned by dbo. To do this:
On the computer running SQL Server, open SQL Server Enterprise Manager.
Expand the Microsoft SQL Servers node.
In the console tree, expand the SQL Server Group node.
Expand the (local) (Windows NT) node.
Expand the Security node.
In the details pane, right-click sa, and then click Properties.
On the Database Access tab, in the Specify which databases can be accessed by this login section, select the database.
In the Database roles for database_name section, select the db_owner row (the check box should already be selected).
In the Database Role Properties – db_owner dialog box, ensure that dbo is the only user listed under Database role type. If any other users are listed, select them, and then click Remove.
Click OK twice.
Close SQL Server Enterprise Manager.