Error:
Cannot find the certificate request associated with this certificate file. A certificate request must be completed on the computer where it was created.
Issue,
The certificate is still being processed and has not yet been added to the server.
Resolution
Click ok and wait
After waiting refresh (F5) the certificate window within IIS.
You will notice that the SSL certificate is missing a friendly name, in order to fix this you can do the following.
Start > RUN > type in mmc and click enter
Click File Add/Remove snap-in
Double Click Certificates > Computer account then next, Local computer then Finish, OK
Browse to Personal > Cerfificates then right click the new certificate and click properties, Enter a Friendly Name and click OK.
You can close all windows now.