As @sarathi125 suggested, Directory.Move method moves a directory and all its contents, including nested subdirectories and their files, to a new location and if the destination directory already exists, an error occurs.
You cannot use assign activity because return type of this method is none.
You can write this code in invoke method activity with the following options:
- Target Type as System.IO.Directory
- Method Name as Move
- Two parameters in property panel with In and String Type for SourceDirectory and DestinationDirectory.