[split] Missing newton.dll

[CanT]

FATAL ERROR "Couldn't load PointLight2D"

This error occurs when the exe file is run from the wrong directory. Could you check so Requiem.exe is really in
"[path to black plague]/redist"
so if
"C:/Program Files/Paradox Interactive/Penumbra Black Plague/"
is your path, the exe should be located in:
C:/Program Files/Paradox Interactive/Penumbra Black Plague/redist/"

yep, that's right
maybe there is point to check something in Windows Registry?