If you still have your serial number but need the authorization code, you can use the SketchUp License Manager to have it resent to the email on file. On-Device Retrieval: If 2017 is still installed on an old machine, go to Help > License (Windows) or SketchUp > License (Mac) to view the active serial number. 🛠️ Activation Process (Classic License)

: Click the Add Classic License button (ensure you are on the "Classic" tab, not the "Subscription" tab).

This was the paid version that requires the codes mentioned above. A Note on "Free" Codes Online