The company who runs the Datacad licence servers has been hit with a multi server failure of some sort. They have been working to get things back up all day. From a post on the Priority Service Plan board:
Mark F. Madura wrote:If you're in a jam due to the current server outage, you can perform a manual activation. Go to the Windows Start menu and highlight the DataCAD program group. You should see a License Actions sub-folder. Select Activate DataCAD from there. This should force DataCAD to launch with the Activation dialog. Select Activate Manually, then enter your license ID and password in the next dialog. Select continue to see User Code 1 and User Code 2. You can e-mail these values to help@datacad.com along with your DataCAD version and edition (i.e. DataCAD 16 Subscription Edition, or DataCAD 17 Professional). We will then reply with Activation Code 1 and Activation Code 2 which you can use to activate DataCAD.
Note: User Code 1 is automatically generated each time you run the activation, so don't dismiss the dialog before receiving the activation codes from us.