Signal 4 is SIGILL, which makes me wonder if the CPU in the machine you’re running ML on is too old to support the instruction sets we’re using.
We’re using SSE4.2. There’s a list of the CPUs that support it here: https://en.wikipedia.org/wiki/SSE4#Supporting_CPUs
Is your CPU listed as supporting SSE4.2 (or newer than the ones on the list)?
If not, would you be able to add a newer machine to your cluster to use as an ML node? You could set node.ml to false on all the other nodes to ensure ML jobs only get run on the newer machine.