Exporting hi-res image errors because it's too large

Hi guys.

I'm trying to export hi-res image but can't do it because it's too large.

I've searched same problems but still failed to solve this problem.

I tried another smaller file and it was OK.

How can I export hi-res image with this file?

Thank you

Rhino Version 5 SR12 64-bit (5.12.50810.13095)