- Black field occurred in third-party program such as EDM Model Server Manager, when Thunderbolt display is connected.
- Virtual machine freezes when Thunderbolt display is connected.
When the external display is connected the guest system switches from the Integrated to the Discrete graphics processor. The issue occurs because the guest system OpenGL cannot switch the graphics card.
Disable 'Automatic graphics switching' on the Mac to use the higher-performance discrete graphics processor at all times:
Use the checkbox labeled 'Automatic graphics switching' at the top of the Energy Saver panel of System Preferences to disable it:
Switch your virtual machine from Longer Battery Life to Better Performance:
Open virtual machine Configuration > Options > Optimization > Power > Change it to Better performance:
- Shut down the virtual machine before connecting the external display.
- The virtual machine should be working fine.