A Classic License can activate specific versions of SketchUp. Follow these steps to authorize a the version of SketchUp associated with your classic license:
- Download and install the version of SketchUp you wish to authorize. SketchUp only provides download links for supported versions.
- Open SketchUp. When the Welcome page appears click Add Classic License.
- In the License window click Add License.
- Enter your User Name, Serial Number, and License Key.
- Click OK.
Authorizing SketchUp Pro 2019 with a Classic License