In RDS Configuration, Test Connection is Succeful, but Test Debugger fail?

In RDS Configuration, Test Connection is Succeful, but I click Test Debugger

Test Debugger failL

"it said : An RDS connnection was established but the ColdFusion RDS line debugger could not be contacted.  The server gave the following message:  Coldfusion line Debugger is not enabled."

My Server is running normal, connection is OK!  How to fix?