To answer your question: 1
1960, pen and paper was useful back then. Pen and paper is still useful, try to beat the computer with pen and paper.
I know that the crop view is a pain to adjust using a curve. I try to not use it so much. Sometimes a circle will do...
I would try to remove the curve and redo it. It should not crash. Maybe you have some constraints to it that makes it fail and drop out.
Thanks, Daniel, I simply delete and create new one rather than edit. I cannot believe something so simple crashes the software. Likewise, polygonal selection in Photoshop has been crash prone since at least 2004. I don't understand how expensive softwares can skip the basics like this.
I have felt the frustration. Remember, it's not the spline that's killing your computer. It's the intersection of that spline with all of the entities in that view, projected normal to the plane. You have to project that spline surface down through the model, then calculate the intersection of every entity in the assembly (all of them defined on arbitrary planes) with that non-linear surface, then figure out whether any of them are zero-thickness, and probably a lot more non-linear ops that are escaping me because I'm not smart enough to write this algorithm. Non-linear = death, in all except the most preposterously simplified problems.