Cumulative Sky won't generate?

Hi Friends. I'm new to Ladybug and I have been having trouble with radiation simulation. I installed Radiance and manually copied the gendaymtx.exe file to my working directory folder. My problem is that Gendaymtx only runs for a split of a second and it doesn't seem to be generating the sky data needed (I also switched off the useOldRes toggle to make sure it runs every time). I'm getting KeyError from the SelectSky component and the sky visualization is completely blank. I used epw data from NYC and Osaka to test and they returned the same results.

Please help. Thank you!

*Update: I read all other threads on this forum about this issue and did replace the gendaymtx.exe with the links provided in those threads - still negative.