Please try the build above and let me know if it works for you. It works for me on my Windows 8.1 x64 system running Photoshop CC 2014.
Wow, an issues seen in PM5, that seemed to point to Photoshop CS2014, but turns out is actually a Windows problem itself.
It works! The only small issue is that if Photoshop is not already loaded in the background, you get a pop-up from PM5 saying "Error: couldn't send photos to editor application." and then PM5 launches Photoshop it is too late by that point. If you click "OK" on the dialogue box, and try to open selected images again, it works since Photoshop is now loaded.
So not sure if there is a workaround for that, or if not, maybe modify the text to add "... please ensure application is loaded first and try again" or something like that so the user has better instructions as to why there was an error.
Thank you for putting something together to get around a Windows issue, this will make my life a lot easier!