It's my mistake to bug you, but there is nothing wrong with the game. The issue was caused by OBS. I followed this article and ran OBS as an Administrator, and the issue got resolved. Thanks for your valuable reply, anyway.
Hello all, I recently downloaded 'Space Quest II: Vohaul's Revenge Remake' from Gamesnostalgia to my Windows 10 PC and it is running smoothly, however, when I try to record the gameplay using OBS, I only get a black screen. Could anyone help me out? Thanks!