Why am I unable to select some windows as a source?

In Windows, minimized windows are still visible in the window list; they simply won’t be able to render anything in the mixer if they’re minimized. Chromium-based apps (ex. Discord) cannot be captured exclusively due to technical limitations.

In Mac, there are many special windows that might be hidden for various reasons. Even fullscreen (maximized) windows are considered hidden; the macOS API does not distinguish between various kinds of “hidden” windows. In this regard, we are hiding all hidden windows from the list.