Please follow mentioned steps
- Login to Virtual Center using Web or vSphere Client.
- On top of console, you can see the note saying that licenses in our inventory either expired or not available.
- Go to Home > Click on Licenses under Administration Tab
- Click on Manage your Licenses in Getting Started Tab or Go to Licenses Tab.
- Click on + icon to Create New Licenses.
- Enter the vCenter Server 6.x Standard license key and press Enter to add a new line.
- Enter the vSphere 6.x Standard license key(For ESXi), and click Next.
- Label the license keys as per your convenient. Click on Next.