Available from version 2.8 b1024, users can now choose an alternative way to handle FTP connections in Omniscope, that it may help to reliably load and save data from/to various FTP servers, through different network configurations.
So in case of DataManager blocks struggling to open remote sources from FTP server, or Omniscope not able to open/export files from/to remote FTP server, you may try to enable the "Use Apache FTP Client" option into the "Settings > Advanced > Networking" menu, restart Omniscope, and then test the action again.