Howdy,
So there is a bug where if you select region render (in the c4d viewport) and click anywhere in the viewport - this action is going to crash c4d without a save.
Do note, if you click & drag a region render it works perfectly. It is only crashing if you create a 1x1 pixel region render by just clicking anywhere in the viewport once you have region render selected.
I cannot reproduce this from your description as it is. Could you test if this still happens in A6.2? Corona for C4D A6.2 testing - Corona for C4D :: General - Chaos Forum
What OS are you on? Does this happen in all scenes? What about render settings - did you change anything there?
Sorry for taking five years to respond to you… Was quite busy
So it seems I can’t reproduce it anymore. I used (before A 6.3) to but not anymore and I have no idea what changed.
Thanks though!
Well, I’m glad it’s OK now. And it was not 5 years, but 32 days - not so bad after all 
Ugh, so sorry about it