Did you buy direct from Adobe, or from some other vendor?
Cloud programs do not use serial numbers... you log in to your paid Cloud account to download & install & activate... you MAY need to log out of the Cloud and restart your computer and log back in to the Cloud for things to work
Some general information for a Cloud subscription
Log out of your Cloud account... Restart your computer... Log in to your paid Cloud account
http://helpx.adobe.com/creative-cloud/help/install-apps.html to install or uninstall
Cloud Getting Started https://helpx.adobe.com/creative-cloud.html
-Install, update or UNinstall, and launch after installing
The CC has been activated as of today, the activation server confirms about it. It is under this Email ID only.
Having similar problems. I had LR, then moved to creative cloud. I was getting a message to enter my serial number. I was just selecting trial and using that instead as I didn't know how to fix it. Now its telling me that the develop module has been disabled, I think because the 'trial' has run out. My payments are unto date, I'm receiving receipts for payments made but cannot figure out how to sort this out. I've also uninstalled LR, reinstalled from the CC app, and restarted my computer, still nothing. One thing I have found is that when I go into manage my account I get this message:
We are unable to load all your plans & products. Please try again.
Can anyone help please, I have urgent sessions to edit...