Hello,

Sorry to hear you are having trouble.

I have really not seen that not work, where Ctrl + Alt + Backspace (in combination with the alt monitor button) did not render the remote desktop.

That said (and perhaps not to the extent you want to test), these HDMI emulators should resolve the issue.  They are dirt cheap as well:

https://www.amazon.com/s/?ie=UTF8&keywords=hdmi+emulator&tag=googhydr-20&index=aps&hvadid=229087316358&hvpos=1t1&hvnetw=g&hvrand=7290124805200557823&hvpone=&hvptwo=&hvqmt=b&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9016897&hvtargid=kwd-298657188227&ref=pd_sl_8sv9d7soo7_b_p37

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Sean Drohan
Stardock Customer Service Manager

Alex - did the emulator resolve this for you?

I am seeing the exact same issue.  All was working normally, then I left for a few weeks of vacation, return home to a lot of Win10 updates on both PCs, and now, my secondary machine MUST have a monitor plugged in, or the primary gets a black screen.

The connection stays active, but the screen is black.  Key strokes still transmit to the secondary from the primary.  There is just not video appearing to the primary - black screen. 

If I connect with the primary to the secondary while the secondary has a monitor plugged in (HDMI), KVM works normally.  If I unplug the monitor from the secondary, it stops updating video in the primary's KVM window.  If I plug the monitor back into the secondary, all resumes normal functionality.

Is there no setting anywhere to adjust this / correct this?  From what I can see, this breaks Multiplicity entirely for me, and I suspect we aren't the only ones.

I suspect I will end up ordering one, then.  Thanks for the quick reply, Alex.

Sean, there are clearly multiple cases of this occurring - any ideas what changed in the update and if there is a software setting to remedy this as opposed to needing a physical dongle?