If your organization uses a managed by an ArcGIS License Manager on a network server, follow these steps.
This happens if the software cannot reach the network license server or if a single-use registry key is corrupted. Check your internet connection, verify your firewall is not blocking outbound ports 27000-27009, or re-run the ArcGIS Administrator to verify your license status.
Choose (If your machine is completely offline, select "Authorize at Esri's website or by email" to generate an authorization file).