When activating Dashboard Server you see the following message:
"This key has expired"
Some license activation keys (such as for technical preview releases and evaluation licenses) are only valid for a limited time period. Contact SquaredUp Support to obtain an up-to-date activation key.
For other renewable licenses you will normally be able to renew your license before it expires. As part of this renewal process, Dashboard Server will update your existing license with the new subscription term, so you can simply reactivate your license for the changes to take effect.
If your license expires before you are able to renew then you may be sent a new license activation key, which you should paste into the activation screen to activate the new key, when prompted when you open Dashboard Server.