thanks for pointing to this issue. It seems to be the same as reported for A-MQ 7 (based on Artemis 2.x) [ENTMQBR-915] Receiving Text message sent via Core 2.x cannot be received with Core 1.x which is closed however it appears not to pass through proper verification. I'll ask ;-)
What version of the server you are using.
I needed to change the server to fix the compatibility issue. Depending on the version of the server this could still be an issue.
We have added compatibility tests on the Artemis Testsuite doing a mesh with different servers and different clients. Unfortunately there was not a way to fix the compatibility on previously servers.. you will need to update the server.
If you still hit an issue with a 2.5.0 server and 2.5.0 client <-> 1.5.5 client.. then we need a way to replicate the issue and understand what happened. as the work on the testsuite was quite extensive.. perhaps you found something I didn't look when I tested.
But most likely you are using an older server's version what will cause the issue.
So, are you sure you are using 2.5.0 server? I bet you are using 2.4.0 Server, 2.5.0 client and 1.5.5 clients
You were right. Due to a mistake it was still using the 2.3.0 broker. Updating to 2.5.0 (and making sure it really is 2.5.0) fixed the problem.
All of these constellations are working now:
1.5.x -> 2.5.0 -> 1.5.x
2.4.0 -> 2.5.0 -> 1.5.x
2.5.0 -> 2.5.0 -> 1.5.x
Sorry for taking your time.