Help!! Can't activate Cubase 8!

Followed the steps, but still no good. Same as before. I get a ‘Recovering License Transactions’ dialog box containing this message:

'An error occurred which prevented the operation from succeeding.

Please restart your computer system and try again, or contact your software vendor’s support department in case the error persists.

Click ‘OK’ to proceed with further maintenance tasks, or click ‘Cancel’ to stop the maintenance procedure.’

Oh dear…