I have purchased a premium voucher but it says Validation failed could not connect to server .Check internet connection and try again. My internet works fine.Is there a problem with the voucher ??
More info. would help, like what OS are you using, any 3rd party firewalls ect.
First step, make sure it's not being blocked by your firewall, you may have to add it to the allowed list of programs.
If you do this step and its not solved, try removing the software and cleaning up with something like Ccleaner to cleanup any leftover drivers then reboot, try re-installing software.