Raytracing render stops

Not really, sometimes it works, sometimes it won’t, even with what I thought being tricks.
I wonder if the problem could be linked to another 3D app running at the same time.
I began to make a serie of screeshots to illustrate, with a single sphere, and while I was preparing this, the rendering was suddenly not stopping anymore.
Quite an erratic behaviour on my iMac.
I’m using an evaluation version, I don’t know if it can be an explanation.
Anyway, I think I’m going to buy Rhino, even with this problem it’s a beautifull software, very well done, as far as I can compare with all the ones I’ve been using in twenty years (Maya, 3dsmax, Catia and Sketchup), which are, for a part of them far too expensive compared to they provide.

It’s not that. The evaluation is nothing more than a times license. It isn’t a different “version”. The application code is the same.

I hope you can find the mysterious combination that causes the problem. Then perhaps we can do something about it.