Here is a copy of this problem that hit many users. I haven't seen any sign that the support had read the individual threads, so I assume they only read this sticky thread. Feedback on what is reported and what isn't would be greatly appreciated (though it's more easily done in individual threads than in a massive thread with lots of posts).
Since the first EA release, when I start the game from the launcher (either GOG or directly with LariLauncher.exe from the Launch Baldur's Gate 3.lnk), - in DX11: I have a black screen, no mouse cursor, no sound. I waited for a long time to be sure, but nothing is happening and I have to kill the process to get back the control on Windows - in Vulkan: it depends, usually black screen but with waiting mouse cursor, no sound. Or crash to desktop.
I tried to find relevant logs but not sure what would help.
@support: could you please give at least some feedback to say you have seen the problem, and to tell us which logs could help you pinpoint the problem? There's a long thread on that already, but without any sign from you I have to assume you haven't seen it yet, so I've created a new one.
A work-around that works sometimes (1 out of 5-10) is to launch bg3_dx11.exe as admin, maintaining the shift key. I don't see why the user should have to do that for a process which is not supposed to be elevated.