It is important to make sure you have Blackmagic capture card up to date with the latest firmware. You can do this by going to Blackmagic's Support Page, choosing the "capture device" category, and downloading their most recent Blackmagic Desktop Video software and following the update steps.
Ensuring your Blackmagic device up to date is a necessary step in getting your live source into your computer and recognized by Socialive.
Once up to date you will now want to open the Blackmagic Desktop Video software and make sure your newly updated device is recognized by your computer. Depending on your broadcast set up you will also want to make sure the device is using the correct HDMI/SDI input selected on the capture device. You can do this by clicking the icon beneath your device displayed in the Blackmagic Desktop Video software and set your device to receive signal from the correct input.
Now your updated device will be recognized by Socialive upon creating a new broadcast!