I can reproduce this in my little setup.
As soon as I create an Operations node in another Operations node, the vl gui freezes.
I get two exceptions (in a very awkward exception dialog, btw. copypaste is a pain)
when I click continue, the gui is completely unresponsive, after a few seconds the next exception hits.
Cannot delete the faulty node, or have any other way of recovery except killing vvvv process.
Use this to reproduce:
zeromq.zip (99.9 KB)