I created an AWS RDS MSSQL instance using Management Console but I cannot create a new database. Creating a table works fine though.
Did I miss anything in the configuration? Do I need to execute a special schema?
According to the documentation, you can create up to 30 databases per RDS instances. http://aws.amazon.com/rds/faqs/#2
We would need more details to debug your particular issue. (Parameters used to create the RDS instance, exact error message etc )