In general form's object inspector, the compiler asks whether to remove the event handler, if the corresponding procedure is not found in the unit file.
This is not applied to TFPWebModule. When I assign an action's event handler, e.g. OnRequest, and then I delete the procedure from the unit file (so the procedure name remains in the object inspector.) In this case, the application compiles without any error or warning. But the application just issues 500 error when it is called from web browser. I can detect this error if I access localhost, but not xxxxx.com, etc.
Hope the error is detected at the compilation stage.