When I registered essential they gave me the offer during the registration. I took them up on it.
 
Transaction with credit card was uneventful, immediate, and transparent. I was able to immediately download a personalized editor version which had the new serial /reg number already in it. I didn't have to even add it.  I did have to remove essential first so that when I installed the download it would know it was editor.
 
Thing is, I live in Milton, Wisconsin, which is the center of the universe, if you are a cow.
 
If it worked so well from this backwater, I'm surprised that anyone in civilization would have an issue.

TomHelvey
When I registered the Celemony essential they sent me an offer to upgrade to the editor version for $149. I went to the web site to purchase the update. After filling out my card info I got a screen telling me that either my card number or security code was wrong and the purchase was declined so I filled out the information again and retried thinking I had gotten a digit wrong but got the same result so I tried another card and got the same result.
I then received fraud alert emails from both my credit cards. When I checked my accounts it turned out that all the purchases had been successful. Now I am out $450 with no upgrade.
I suspect there is an issue between their German credit card processing service and the US based banks. Instead of having a smooth update experience, I now have to deal with their support across multiple time zones to get the charges reversed. What a nightmare.
I've never had a problem purchasing anything through the Cakewalk site, if the same offer was available there my life would be a lot more joyous right now.

I had a similar problem. I hit "pay now" and it came back and said it was declined. Within seconds I had a message on my phone for a fraud alert. I also had an email. I answered the security questions on my phone (through the Amex app). I called the CC company just to make sure everything was OK. They guy on the phone lifted the alert and verified that it was rejected and no payment was made. He waited while I tried the purchase again. It went through smoothly and I am now downloading.

Please contact Celemony. I am sure they will clear up any issues.

And please mark the thread as "solved" when they do.

Perhaps the title should be - "BEWARE - Credit Card Companies."