Invalid AMFX packet error

Hi I'm testing FDS under Tomcat on Https with a self-certificate
and i'm getting this error message

[MessagingError message='Invalid AMFX packet. Content must start with an <amfx> node']
at mx.messaging.channels.amfx::AMFXDecoder$/::decodePacket()
at mx.messaging.channels.amfx::AMFXDecoder/decode()
at ::HTTPMessageResponder/completeHandler()
at ::ChannelRequestLoader/::callEventCallback()
at ::ChannelRequestLoader/::completeHandler()
at flash.events::EventDispatcher/flash.events:EventDispatcher::dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at flash.net::URLLoader/flash.net:URLLoader::onComplete()