Render Region in Picture Viewer problem

[chanson78]

I just did a very large 2400x2400 px render in the c4d Picture Viewer and need to re-render a small part of the render to cover up a mistake but I am having problems using the Octane Render Region function. Every time I check the box 'Enable Render Region,' Cinema 4D just gets stuck with the 'spinning rainbow wheel' and I eventually just have force quit the application.

Any solutions to this? I would be great to use the Render Region function instead of having to render the whole thing again.

C4D 16, Octane 3, MAC

[aoktar]

How it's happening? When just enabled by checkbox without rendering?
It's working fine on me. Can you test it on a new scene?

[niestudio]

I've used it quite heavily as well, and it works as expected. Same setup here; Mac, r16, octane 3