I am able to download a response as a PDF right now - try another web browser to see if it works.
What browser and operating system is this on?
I am using firefox though there was an update recently so i will see if it works with internet explorer.
More info soon...
I just spoke with one of your collleagues (the document author) by telephone. We've confirmed that there's an issue with exporting responses from this particular form. If you can hold off on doing any more exports until we've updated you that would be very much appreciated. Thanks so much!