Amazon has changed how they set up RDS and link security groups via the API. Due to this change and the fact that Heatmap Tracker adopts the latest version of the Amazon AWS API, the application is not able to create Amazon RDS instance automatically on certain older AWS accounts.

So your options are to either create the RDS instance manually inside your Amazon AWS dashboard and link it to an open security group (allow inbound access), or alternatively you can create a new Amazon AWS account (simply use a different email address to create a new account) and use the new account within Heatmap Tracker to let it create the RDS instance for you on the new account.