I know this wont directly solve your problem, but I found post from 2004 referencing that .exe and that the scene pack is already included on the current version of R4. I could be mistaken, but perhaps if you re-installed R4 from scratch, it'll fix the issue and you'd still have all the scenes from the update as it is part of R4's standard library?
I didn't even know of that update until now though, but I assume those additions (save a few new scripts in the custom scenes forum) are already included in the newest update of R4 itself