It is too early for me
I am using jSerial v1.31 and the new jssc and the other library file as pointed out in the messages above.
I have deleted the .jssc folder under my Windows profile.
I have pointed B4J to the javac.exe that is in the OpenJDK 11 folder.
The chat program seems to work (except that I cannot open the designer, I get an out of memory error) when B4J is pointed to OpenJDK 11. I have not checked that it actually sends data but it does not crash when opening the port (that is when running from within the IDE)
My project also works when running from within B4J when B4J is pointed to OpenJDK11. I can open the designer with my project. (that is definitely an improvement, before it would not even run from within B4J)
When running the packager, the Chat.exe crashes. I can see the outline of the form popping up then it closes immediately. My project does the same.
I actually have two versions of OpenJDK 11. I have 11.0.1 that I downloaded from the B4X web site some time ago, and I have 11.0.2 which I downloaded from the OpenJDK web site also some time ago. They both do the same thing.
I have attached the project.
Point to a valid COM port and click "Send Test Data". If the button turns green, you are OK, if not, then not...
Now, please don't sweat it on my behalf. It is frustrating not to be able to run with OpenJDK but as long as it works with Oracle Java (and it does at the moment), I am not dead in the water. It's just that I don't like the potential licensing issues with Oracle.