Recently I installed ArcGIS for Server 10.5 on our server, but I have an issue. I have authorized the software without any problem, but when I want to create a new site it says:"Failed to create the site. the machine doesn't have a valid license.".
Does anyone know how to solve this problem?
Ensure that the license hasn't expired. If the issue persists even if the license is valid, get in touch with your Esri Tech Support to resolve the issue.
FYI: If you are upgrading from previous version, you will need new authorization file for ArcGIS Server 10.5. You can access your new authorization files in My Esri with your organizational account (with admin rights) or contact your local Esri distributor. License files of 10.1-10.4.x won't work with 10.5.
If a previous version was on the machine, there may still be a license folder associated with the previous version. This may cause problems, so if one exists, you can delete or at least move that folder.