I just tried to launch the latest nightly on windows. The launcher does not start at all and openmw.exe throws the following error:
Could not initialize SDL! Application didn't initialize properly, did you include SDL_main.h in the file containing your main() function?
I tried 0.28.0RC1 as well as the previous nightly and both work fine.
I just thought I'd let you know since I haven't found the error being reported yet
EDIT: Yeah, 64 bit here as well. To make sure, I also tested the 32bit version which behaves the same