Your security SSL certificate may have expired or is about to expire, so you need to generate a New Certificate Request. However, the option is grayed out in the Add dropdown.
This article provides information on how to enable the option to generate a new certificate request.
This happens when the existing Local Authority certificate has expired. You will need to generate a new Local Authority first and delete the obsolete ones. Then the option to generate a new certificate request will be active.
To generate the Local Authority certificate, Go to Configuration > SSL Certificates.
Click Add > New Certificate for Local Authority.
Enter the details and click OK.
The option to Generate a New Certificate Request is available.