I just noticed that [dropfile] doesn't work with my standalone on a Win8 PC when with the exact same standalone it works on a Win7 PC. When dragging and dropping from Windows Explorer onto my drop zone I get the black-circle-with-a-slash-through-it icon.
I googled around and people are reporting drag and drop not working (in other apps) in various circumstances in Win8 when it worked in Win7. It seems to have something to do with a mismatch of user privileges between Windows Explorer and the program in question. A popular "cure" suggested is to left-mouse-down on the file in Windows Explorer, hold it, and press the Esc key, but this did not work in my case.
What did work was to open the Properties window by right-clicking my standalone .exe and setting the Compatibility to Windows 7. Strangely enough, it continued to work when I turned this setting off again...
I had the same problem with Max 7 on Windows 10, only to realize that it was indeed a mismatch between user privileges. Only, in a very counter-intuitive way, I actually had to remove Max's administrator privileges. I always ran Max7 as an admin because otherwise some things would not work properly (I can't exactly remember what, but I think it had to do with running M4L on a version of Live that needed administrator privileges).
I had trouble finding info online about this, so I'm wondering if the problem arises from the particular configuration of my PC, from Win 10 or from Max7.