Coherence mode and External Monitors

Discussion in 'Installation and Configuration of Parallels Desktop' started by JerryB3, Nov 22, 2016.

  1. JerryB3

    JerryB3 Junior Member

    Messages:
    12
    FYI, it still doesn't work with external monitors plugged into the Thunderbolt ports.

    Its just a black screen where the image of the applications should be.

    Works fine with no external monitors. These are 2K Dell monitors.
     
  2. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

    Messages:
    3,158
    Hello JerrryB3, Hello, please be informed that Parallels Desktop 12 Update 12.1.1 (41491) was released and it resolves an issue with Windows virtual machine resolution with "Best for external displays" option enabled when using Windows only on external display. Please update Parallels Desktop to the latest build. Latest version always available here: www.parallels.com/directdownload/pd12 Please note that Parallels Tools also needs to be updated (Actions > Update Parallels Tools) and let us know how it works. Thanks!
     
  3. JerryB3

    JerryB3 Junior Member

    Messages:
    12
    Do you guys even test before you reply to these threads? All y'all do is say upgrade and it never fixes the issue. I have upgraded the install and the tools. Rebooted both the host and the guest and still nothing. I'm willing to give info to fix the issue but since I've posted this issue (since 12 has been released) no one has asked for anything. I tried downgrading to 11 and the issue is still there so It might be related to macOS
     
  4. RoverT

    RoverT Bit poster

    Messages:
    7
    Just installed today using the version you recommended and have the same problem. I've increased memory to video (768 MB) and still not joy. Works fine on the laptop, but as soon as I start adding external monitors through thunderbolt ports, windows go black.
    Other solutions?

     
  5. MarkM15

    MarkM15 Bit poster

    Messages:
    1
    For anyone looking for a fix to this issue (Would be nice if Parallels actually fixed the bug)...
    Under the VM Configure => Hardware -> Graphics setting:
    You CAN NOT set the Graphics option to "Best for Retina display" OR "Best for external displays"
    You MUST set it to "Scaled"
    After setting to Scaled, it appears to work.
    I'm running:
    • Parallels Desktop 12 For Mac
    • Windows 10 VM
    • Two external monitors connected via Thunderbolt
      • Separate cable for each monitor, no daisy chaining
     
    Last edited: Dec 19, 2016
  6. RoverT

    RoverT Bit poster

    Messages:
    7
    Sorry MarkM15, but I have it scaled - no joy. :-(
    Window displays find on my laptop, but as soon as I bring it over to an external monitor, it's all black.
     
  7. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

    Messages:
    3,158
    Hi @RoverT Are you using Windows 10 virtual machine? If so, please let us know how do you connect to the external monitor to your Mac? Via thunderbolt -USB C adapter?
     
  8. RoverT

    RoverT Bit poster

    Messages:
    7
    I'm using Windows 7 in my virtual machine, with an Apple thunderbolt to VGA connector.
     
  9. PaulChristopher@Parallels

    PaulChristopher@Parallels Product Expert Staff Member

    Messages:
    3,158
    Dear @RoverT, please check out the instructions as mentioned below to fix the issue:
    1. Go to Mac > System Preferences > Mission Control.
    2. Enable Displays have separate Spaces option.
    3. Log out from Mac user account and log in back.
    4. Enter Full-Screen view mode with your virtual machine. To extend virtual machine to the external display go to View menu of the virtual machine > Use All Displays in Full Screen.
     

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