Were you following the instructions word for word? I wasn't. Therefore, I got into trouble.
Here's my story: After talking to support, I went to the the PCMS builder download, and under Support Resources, download the file. I re-read them carefully, something I failed to do the first time, and followed them perfectly. Once I did that, I had no issue. It works perfectly.
In a nut shell, I was uploading CMS and using that serial, when all I needed to do was upload PCMS and use THAT serial.
If, unlike me, you followed those instructions and it still isn't working, then I cannot help.