Issues connecting to Virtual Machine from Mac client WITHOUT external monitors, OK with monitors

[jayholley]

• Mac Horizon build 2306, freshly reinstalled
• MacBook Pro 14 inch, 2023, macOS Ventura 13.5.2

I'm experiencing an odd bug connecting to my corporation's virtual desktop from my personal MacBook (M2).

• When connecting to the remote host in "pure laptop" mode, without any external monitors plugged in, the Mac successfully connects to the server, but then the resulting virtual desktop screen I see is in a strange "limbo" mode. I don't see the Windows desktop icons, just a gray screen, but you can hear Windows system sounds in the background and the cursor switches to Windows instead of Mac cursor types. 
• If I plug in my Mac into either an external monitor connected direct to the HDMI port, or to an HDMI port indirectly through a USB-C dock, I can connect to the virtual machine with the PC graphics displayed as you would expect. A great experience. I can selectively use the Mac internal display, either of the two external monitors, or all three.
• Here's a fun bit... if I connect with external monitors plugged in (establishing a successful remote desktop) then unplug the monitors, Horizon figures out how to gracefully deal with the change and will reduce to showing the remote machine JUST on my Mac laptop's internal monitor. So there seems to be something going amiss in the initial connection, since Horizon can clearly make everything work.
• I have reinstalled Horizon, tried multiple alternate resolution settings in the horizon client to see if that might be the issue, and switched the connection protocol from Blast, and back. No dice.

Any ideas appreciated? Frustrating as this is keeping me from using my remote "architectural workstation" on the road from my Mac, which is amazing (thank you VMWare!).

[zhanglin999]

Hi, Jay,

We have heard similar issue recently, and suspect that it may be related to different CPU models of Apple Silicon, so it would be helpful if you can share more details about your CPU and GPU, because MacBook Pro 14 inch, 2023 has 2 CPU types. 

Also you can try this workaround to see if it works in your case:

1. Open terminal from /Applications/Utilities/Terminal.app or /System/Applications/Utilities/Terminal.app
2. Run "defaults write com.vmware.horizon kDisableMetal YES" in terminal
   
3. Re-launch Horizon Client to see if the issue still happen.

--zhanglin

[jayholley]

zhanglin:

Thank you for taking a look, and the workaround.

More info about my laptop:  

Model Identifier: Mac14,9

  Model Number: MPHF3LL/A

  Chip: Apple M2 Pro

  Total Number of Cores: 12 (8 performance and 4 efficiency)

  Memory: 16 GB

  System Firmware Version: 8422.141.2

  OS Loader Version: 8422.141.2

The workaround at least at a quick test appears to work -- I was able to open up my virtual machine all appears to be normal. I will make a point to use in pure "laptop mode" without external monitors more in the coming week so I can report back any anomalies, but that mod seems to have enabled things to get running. Many thanks.

Jay

[jayholley]

After using for several days, workaround seems to work without issue.