Please check your internet connection. You should be online to use premium.
If you're using antivirus software/ firewall/ proxy, deactivate them temporary please or add DVDVideoSoft programs to the exception list. Try to activate the application again. Will you have same problems?
If the problem still persists, send the program log files to our support:
1. launch the DVDVideoSoft app
2. go to Help - Collect logs
3. Send '_logs_to_send' as an attachment (or just drag-and-drop the folder on the ticket page)