IllegalArgumentException when calling NettyServer#stop

As shown in this trace, I get an IllegalArgumentException when I call the stop method of my NettyServer instance.

The definition of my NettyServer instance is available here.

I see in the documentation of BatchingExecutor that I am “inside, but I’m not sure what this means.

Does someone has an idea of where the failure comes from?

I’ve just seen that my problem seems to be the same as