Firewalls or antivirus software are blocking communication between SAP2000 and the Sentinel RMS server.
: Ensure you are running a compatible version of the license manager. For example, SAP2000 v18 and newer often require Sentinel RMS License Manager v8.6 or higher to recognize modern licenses. sap2000 license not recognized error 18 fixed
On the server, open the Services menu ( services.msc ), find the Sentinel RMS License Manager service, and restart it. sap2000 license not recognized error 18 fixed
Are you using a license or a network license for your SAP2000 installation? Licensing errors generated when running CSI software sap2000 license not recognized error 18 fixed