No 'ack' header in MESSAGE frame

Question

I have a subscription client that subscribes to a topic (not a queue) on ActiveMQ Classic 5.16.2 via STOMP. In order to manually acknowledge MESSAGE frames using the ACK frame to the message broker, the client passes ack:client in a SUBSCRIBE frame. But when MESSAGE frames are received in the client, there is no ack header available in them. Why? Is there some configuration missing?

Answer 1

The syntax of MESSAGE and ACK frames are slightly different among different versions of STOMP. Once the client sends the CONNECT frame with accept-version:1.2 option, all worked fine.