After downloading Cheetah Solver plugin from Autodesk App Store (or from our site) you need to activate it before starting the first session. To do this click the Activation button in the Cheetah Solver Plugin group of Add-ins tab in AutoCAD ribbon control:
After that you’ll see the following dialog:
You should enter serial number (that you received by e-mail) in corresponding edit control (or copy/paste it from e-mail) and push “Activate” button. Not that for on-line activation you should be connected to Internet.