3ds Max Render Stuck: CPU Goes to Idle Process Instead of Rendering

Corona Corona for 3ds Max Issues
1

Hello everyone,

I’m facing a frustrating and recurring issue with Corona Renderer in 3ds Max. As you can see in the attached image, my render is not starting. I’ve waited for over 8 minutes, and the renderering passes did not started yet.

When I check the Task Manager, I see that the System Idle Process is using most of the CPU, while the Corona render process is consuming very little. My RAM usage is also low, I have 128 gb, and only using 65 gb .

This problem sometimes goes away if I restart the windows, but it quickly returns, which is making my workflow very difficult.
What could be causing this, and how can I fix it permanently? Any help or advice would be greatly appreciated.

Thanks!

Screenshot 2025-08-21 030220.jpg
Screenshot 2025-08-21 030220.jpg965×518 174 KB

2

Hi, sorry for the delay, your thread somehow wasn’t marked as new for me.

If you are still getting this problem:

  • Please let us know which exact version of Corona and 3ds Max you are using
  • What is your CPU model?
  • Is this happening only with batch rendering or also if you render from F9 / F10?
  • In your screenshot, the rendering has actually started - it says “rendering initial pass” which basically means that Corona is rendering its first pass

If you have a scene where you can consistently reproduce this, please contact us at https://support.chaos.com/hc/en-us/requests/new and attach that scene.

Thanks in advance!