Hello,
last week we have the same Problem. We have NetSight 7.3 and make a Backup. After restore the Backup in NetSight 8.0.5 on a new server, the Restore was failed. After this issue it was not possible to beame a log in window. So we upgrade the NetSight 7.3 to 8.0.5 backup the Netsight and restore it on the new Server.