Can't Export to STL

I have tried to export a nrrd file of a large CT scan that I have gotten, I go to segment editor and then select the segment I want via the threshold function… I try to do ‘show 3D’ and it doesn’t work. I have 64gb
(upgraded from 32gb) of ram available and a 500gb ssd.I want a STL of this. Any Idea how?

Please elaborate on what happens instead.
Is there anything in the log? (About / Report an error)

application either crashes and force closes itself or goes to bad allocation, I feel as I am doing something wrong setting up the file.

Is there anything in the log? (About / Report an error)

What is the resolution of the CT?

the resolution of the CT is really high, I’m not sure what it is exactly though however…

You can check the resolution in the Volumes module.

If you disable smoothing (checkbox in the dropbown menu of the Show 3D button) then does it show up?

You may need to increase virtual memory size in your system settings (e.g., try to set it to 10x larger than the size of your CT image).