Every time I am feeling confident with Rhino it makes me humble again. I am trying to build a core that I can use as a subtraction from another solid. I am using cylinders, spheres and rectangles to build the object. Depiction below:
I wish there was a dialogue that came up to tell me why it failed or a tutorial that poped up to tell me how to fix the problem as I am expending significant time trying to troubleshoot this issue.