Once the download is complete, follow these steps to install Autodesk Revit 2019:
If you followed every step above and still face a license error, the culprit is almost always a corrupt Windows user profile or a previously installed "trial" that left residues. In that scenario, use the to nuke all Autodesk entries and start fresh. autodesk revit 2019 installation and activation
After reboot, you will see the "Getting Started" screen. This is where 90% of failures occur. You have three activation paths. Choose the one that matches your license type. Once the download is complete, follow these steps