The version you are working on is a "pre-release" version, forced upon us by a change in Windows10 (1607) that broke madCAM. It's basically a work in progress update that's not really ready, but the alternative was no madCAM at all. The simulator is the main reason it's "pre-release". Basically, it's not ready yet. Joakim is creating a simulator that shows multi-axis material removal, but there have been issues with the private pre-release versions that have forced him to continue working on this.
I haven't seen a crash situation like you describe, but if I had to guess I would say it's related.