This might be common knowledge but I figured I would share anyways incase anyone else runs into this problem. We wanted to get a Verisign cert installed on our controller so that users wouldn't receive the "do you want to trust this site" when getting redirected to the captive portal. So we generated a CSR and used that to get our certificate, one important thing to note is when getting the certificate from Verisign it will prompt you to select a platform, choose Linux - Apache. We received the .cer file and then uploaded it and choose PEM for certificate format. Initially we choose the wrong platform when getting the certificate from Verisign and it caused errors when attempting to upload.
Cheers,
Brian