Dual Screen Mode Grayed Out – Why?

Hi everyone,

In previous versions of DaVinci Resolve, I was able to switch to dual screen mode without any problems. But now, in the current version I'm using, the option is grayed out and I can’t enable it anymore.

Does anyone know why this might be happening?
Is it a setting I’m missing, or has something changed in the newer versions?

Any help would be greatly appreciated!

Thanks in advance,
Christophe

The last four replies in this thread have some example reasons, if one helps:
viewtopic.php?f=36&t=160513

At least in the Studio version, v20 working with dual screens successfully.