Hello Helen,
thank you for your replay. I connected the Sync Folders by manual Connection. I started on the Mac OS X Server. There i created the First read and Write Folder in Sync application. Then connect my folder (with the files) from USB Drive to the Sync-folder. I copy the read and Write key and created the folder on my Nas by using the manual Connection.
The USB Drive on the Mac Server is always on. When i connect the Shared Volume (on the Mac Server) by a Client Mac, i can See, copy or change the Files.
i thought it Must be a permission Problem. Sync can´t change the files on the Server. On my Nas it works.