Except it causes problems with OBS' game capture when disabled. Hate it or not, it's not useless.
For win7, Game Capture, full screen games? At least, I can confirm that it can cause performance lag for poor systems at some tasks:
massive fps drop with obs open (no recording or streaming) but improve hooking or texture sharing for full screen applications?! Is it true? I mean, can you bring math or statistic to proof it? Have you test it with OBS Studio application?
As for capturing. Try to create new
Scene Collection (if you updated from previous OBS Studio build, you can delete and recreate 'Game Capture' source). At least it helps me few times after Studio update. Don't know, maybe this the case.
If not, I will suggest you try to capture
fr-043 demo and see able you capture something 3D or not.
Game capture not working (under the spoiler).
I hope your OBS Studio's Preview is black, not video itself, yeah?