If you launch OBS and the image in the main screen of Open Broadcaster is either black or frozen take the following steps;
- Highlight the Video Capture Device in the Sources section
- Click on the properties wheel
- This will take you to the Properties screen
- In the drop down where the capture device is list click on the drop down and select the camera, then select the capture device again. This forces the operating system to re-initialize the capture device.
If that does not work, unplug the capture device from the computer and plug it back in.