No Win10 Fullscreen with DualMonitor after Upgrade to P12

ChristophL1

Bit poster
Hi,
after upgrading P11 to P12 my Win10 machine won't come up in Fullscreen across both monitors.
Have tried some settings with settings bur nothing works.
Only one monitor is used and there is a corrupted TitleBar from OS X (I'm using Sierra Beta 6) on top of the Win 10 Window.

Regards,
Christoph
 
I am having the same issue. I've submitted technical info with report ID 112886047 for this problem.

I have one external monitor connected to my Macbook Pro. Under Parallels 11 I was using fullscreen mode in Windows 10 across both the external and laptop display with no problem. Now the laptop display is just black. I've tried reinstalling parallels tools, increasing video memory, etc. Nothing works.

I've tried both the parallels and Apple hypervisors, and the problem exists in both.

I'm afraid Parallels 12 is not usable for me with this issue.
 
Last edited:
This is still not working after going to 12.0.1. Going full screen on external dual monitor causes the second monitor to go black.
 
In fact, I've something else. When going to full screen on a dual monitor setup each guest screen is in a different space (main screen in space 2 and secondary screen in space 3). I'm using the last build available (12.0.1).
 
Ok I have reproduced this issue on my 2015 MacBook Pro. I had to downgrade to parallels desktop 11 the go back to 12.0.0 to reproduce. I then upgraded to the hot fix PD 12.0.1 and the issue remained. I then made sure use all displays in full screen was selected check all other setting that worked in parallels 11 are still the same. I shut down my MacBook and reset the pram and SMC controller. You do this by shutting down and connecting the power adapter hold the shift option control keys down and press the power key. Hold for a few seconds and you should see the led indicator on your power adapter flash from green to red then back. Now press the power button only to startup OSX and hold down command option p and r until you hear the system chime again and the screen flash like your restarting again then release and let the system boot. Once booted up restart parallels and be sure the newest version of parallels tool is installed. Start your van in a window and drag to your second monitor with mouse. Now go to the title bar and click the green full screen button. You should now have your VM on one screen and OS X on the other. You can use the trackpad to swipe to a second desktop or space for either OS. Let me know if this helps. Thanks
 
I had a support call with Parallels. Explained the issue in detail. They know about the issue and are working on a fix.
 
Interesting... check this out:

http://pubs.vmware.com/Release_Notes/en/fusion/8/fusion-850-release-notes.html

From the 'known issues' section:

[Q]
If more than one monitor is used in Full Screen mode on macOS 10.12 host operating system, the virtual displays are merged into one space in different tabs, instead of creating Full Screen space on each monitor

On macOS 10.12 host operating system, if there is external monitor connected to the Mac machine, when you switch a virtual machine to Full Screen with "Use All Displays in Full Screen" option selected, the virtual machine shows in Full Screen only on one monitor and merges all virtual displays to it as tabs, instead of using separated spaces on all monitors. After changing the view mode back to Single Window, a redundant black space remains, and the Fusion menu bar is hidden automatically.

Workaround: Open the System Preferences on macOS 10.12 operating system, click the Dock icon. Choose "Manually" on the dropdown list of "Prefer tabs when opening documents".
[/Q]

That's almost exactly what happens with Parallels 12 in full screen / multi-monitor mode. I wonder why Parallels 11 didn't have that issue? And why both Parallels and VMWare Fusion now have the exact same problem?
 
Interesting... check this out:

http://pubs.vmware.com/Release_Notes/en/fusion/8/fusion-850-release-notes.html

From the 'known issues' section:

[Q]
If more than one monitor is used in Full Screen mode on macOS 10.12 host operating system, the virtual displays are merged into one space in different tabs, instead of creating Full Screen space on each monitor

On macOS 10.12 host operating system, if there is external monitor connected to the Mac machine, when you switch a virtual machine to Full Screen with "Use All Displays in Full Screen" option selected, the virtual machine shows in Full Screen only on one monitor and merges all virtual displays to it as tabs, instead of using separated spaces on all monitors. After changing the view mode back to Single Window, a redundant black space remains, and the Fusion menu bar is hidden automatically.

Workaround: Open the System Preferences on macOS 10.12 operating system, click the Dock icon. Choose "Manually" on the dropdown list of "Prefer tabs when opening documents".
[/Q]

That's almost exactly what happens with Parallels 12 in full screen / multi-monitor mode. I wonder why Parallels 11 didn't have that issue? And why both Parallels and VMWare Fusion now have the exact same problem?

THANK YOU. :)

I was seeing the behavior you describe, and this completely resolved the issue for me.

MBPr 2012
Windows 10 Anniversary x64
Parallels 12 (latest patch version)
External Dell P2715Q via mDP
 
Latest update does not fix the full screen dual monitor issue. Main screen running MacOS Sierra still turns black when second screen running windows 10 is set to View Full Screen
 
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