Just wanted to post a quick note apologizing for the issues we’re having with serial numbers with Flex Builder 3 Professional. We are currently working with our operations team to get the issue resolved. Apparently the system does not have serials loaded for FB3 Pro, so everyone is getting a notice saying to contact customer service. DO NOT WORRY. This should all be straightened out soon and you will be able to log back into the site to get your serial number without needing to contact customer service.
Additionally, if you have installed the release build and are getting a notice about the trial having expired, you will need to remove your old license.properties file from the beta. Simply delete the file found here:
Windows: %ALLUSERSPROFILE%\Application Data\Adobe\Flex\license.properties
Mac: /Library/Application Support/Adobe/Flex/license.properties