Calico crashes after failed robot connection

I'm working with Calico 3.1 on Mac OS X, generally 10.9, but a few with earlier versions. When the connection to the Scribbler robots fails, Calico crashes, often after trying to run a script a second time, so the connection fails--could be "failed to open port" error or "argument cannot be null" error. Calico stays open and then when you try to run again, it crashes.

This is a frustrating error as the connection fails fairly often.