Specifying a resolution other than monitor's resolution renders the game dark green with wide vertical black bars

[Korwin]

Nvidia GeForce RTX 3070 Ti, driver v536.40
Microsoft Windows 10.0.19045.3208
Baldur's Gate: The Original Saga GOG Edition,  v.(gog-20)
Widescreen Mod 247.00 2021-07-22 — tried UWFHD (2560×1080 px) and 2K DCI (2048×1080 px) resolutions. The monitor resolution does not change when the game starts, and remains native, UWQHD (3440 × 1440 px).

[Jarno Mikkola]

I would need the debug log, aka, the setup-widescreen.debug to know a little bit more about the install of yours.

Edited November 20, 2023 by Jarno Mikkola

[Graion Dilach]

Install https://github.com/FunkyFr3sh/cnc-ddraw/releases/tag/v6.0.0.0 into your game. That should fix it. You don't need the Widescreen mod, because cnc-ddraw has better scaling modes, but you might want to play with selecting a resolution which suits best for you.