HDMI Share requirements.
There are a few requirement for HDMI Share to work properly. Please make sure your setup meets the following requirements:
- Check if your Capture Card is supported. See the list of supported devices: https://quicklaunch.ucworkspace.com/support/solutions/articles/3000089759-supported-usb-hdmi-capture-devices
- Check if your Quicklaunch configurations are set properly. See instructions: https://quicklaunch.ucworkspace.com/support/solutions/articles/3000089650-hdmi-share-configuration-and-usage
- Check if other software like Windows Camera is displaying video feed from the capture device. This will help to narrow down issues with cables, HDMI switches and HDMI ports. HDMI Share is using a different technology then Microsoft Camera application to process video.
How to troubleshoot issues with your graphics card.
If all the above requirements are met but HDMI Share still does not work, you will want to check if proper drivers are installed for your graphics card.
Quicklaunch HDMI Share application requires enabled graphics card hardware acceleration to work properly. If you have configured HDMI Share Settings according to the instructions but HDMI Share window shows black image only, you will want to verify the following details:
- Use our test utility to verify if video is presented on the main screen and what format/frame rate/resolution is used: https://qlinstall.ucworkspace.com/utilities/CaptureManagerTester.zip
If video is displayed in the Main window, please continue reviewing HDMI Share Settings or use Custom graphics settings if your graphics card is using video format other than YUY2 video format.
If video is not displayed in the Main Window, open Device Manager to view Display Adapters list. 
If you see Microsoft Basic Display Adapter, it means that Windows is using CPU to process video using a software called Microsoft Basic Display Adapter. Your actual graphics card is not used.
Proper graphics driver installation resolves this issue. You can determine the graphics card brand name and model on the manufacturer's web site searching with the PC model number, for example Intel NUC8i7HNKQC.
Use DirectX Diagnostic Tool to diagnose issues with the graphics card as well as to get the PC Model number.
Microsoft Basic Display Adapter should automatically disappear on reboot and a proper graphics card brand name and model number appear on the list.