On Windows 10, OBS Studio may capture a black screen even with display added:
The solution is to search for
Graphics settings. Select
Classic App and click
Browse to locate OBS Studio (Default located in
C:\Program Files\obs-studio\bin\64bit\obs64.exe). Click
OBS Studio > Options and try
High performance or
Power saving and restart OBS Studio to see if the capture works.
One of the two options should work. If the issue still exists, see the following reference for a detailed solution.