Broken/Frozen Region Render Box

[Anonymous]

Hi,

For some reason, region render stopped working.  It used to, but now when I select the option, I see a faint gray preview of the box from the last successful region render I did (days ago at this point), but there no handles to drag/resize it, and no little [X] box to exit from it. 
When I activate it, the instructions in the lower left of my UI say "drag to size and place the region rectangle, ESC or right-click to cancel."  However, dragging in the viewport just makes me select geometry. 

Also, the box preview is persistent.  I have tried resetting the render engine and re-opening the scene, but it has done no good.  Is it somehow locked?

Attached is a screenshot of the frozen region window.  Sorry it's really hard to see. 

Max Version:  2017
OS: Windows 10

[Anonymous]

I forgot to mention - this problem is file-specific.  I was able to go to an old version of the file where region rendering still works.  I did many things to it before rendering and realizing the region render problem.  I mainly moved geometry around to new layers, lots of renaming/organizing for a very complex scene... 

[Anonymous]

It's also worth adding that "auto region selected" also does not work.  No matter what object I have selected, the same region renders as the frozen box in the attached screenshot.

[Anonymous]

Update:  I found a workaround, although things still aren't behaving as they used to.  By disabling V-ray's frame buffer and then going into Max's default render preview window, setting render area to View and then Region again, I was able to get the red region render box back, where it can be manipulated again. 

It is now completely missing from the actual viewport.  After re-enabling V-ray's frame buffer, I can now control my region renders in the VFB by keeping the regular preview window open at the same time.  A little clunkier, but at least it works now!

(It is also worth noting that setting "Area to Render" to "Selected" still does NOT work.  The whole scene still renders even when I only have one object selected in the viewport. If I disable V-ray frame buffer and then try to render with an object selected in the viewport, I get an error message. 

This is less critical to me right now, but it would be great to be able to fix it too...)

[Anonymous]

This happens sometimes when you lock the renderer to a camera. It's annoying. But as soon as I unlocked the renderer from a camera it started working again. Worked for me. Hope this works for others.