I’ve just installed Max 2017 and Corona 1.5, having used 2013 and 1.4 for ages.
The first thing I’ve noticed with the new software is that scenes which previously rendered with no problems are now using up all my memory (15BG installed)
Cancelling a render once it’s started also takes about 10-15 minutes
I’m not sure whether this is a Corona or a Max issue.
I have got a similar problems in my scenes
hmmm… my scene’s not quite as large as yours, though there are a lot of corona proxy trees in it.
I’ve also noticed that corona/max’s response to light is a lot different with 2017 and corona 1.5 - scenes that were previously lit quite nicely are now completely dark or massively blown out.
Do you guys think this is related to 2017 in any way? Did you see similar problems with 2016 and Corona 1.5?
Do you have all 3ds Max updates installed?
Do you have all Windows updates installed?
Do you have MSVC++ 215 redistributables installed?
All of that should be installed by the Corona installer, but sometimes there are some errors there, and it is necessary to make sure all is installed manually:
https://coronarenderer.freshdesk.com/support/solutions/articles/12000019570
Everything is updated
I’ve also noticed that the pre-render stuff, like scene parsing and building acceleration structure takes much longer than previously
even rendering out tiny test passes takes forever.
also, there are graphics errors in the render setup window (blank areas that require window to be opened and closed repeatedly)
going to have to go back to using vray
to add to the joy it seems Corona 1.5 is not capable of rendering large images.
I left it running last night on a not-especially-large 4000 x 3000 image and it’s only managed five passes this morning.
It also appears to only be using 9% of CPU resources, rather than the 100% that the previous version would utilise (there is nothing else running on my workstation, and low-priority is disabled)
Imho a screenshot of taskmanager will help the devs to help you to find the solution.
I guess you got out of RAM, it makes the cpu run in low percentage and low at render passes/rays and excessive parsing time.
Wihout out of ram, afaik a lot of people here done their huge renders savely, huge means larger than 4000px to 30000px. My largest render was 8000 x 8000px 
But there was an issue about a type of hi end cpu which is weirdly run in low percentage because it has too much cores, i’m not sure how to describe this kind of problem but you can mention your cpu type too
thanks for the info re: CPU running in low priority mode after memory overrun.
The thing is, in Max 2013 and the previous version of Corona, my memory was only half utilised. Now it all seems to be getting gobbled up.
Hi, we are interested in reports from users experiencing this. Can you please contact us at support@corona-renderer.com with a clear description of the problem and a link to this forum thread?