Actually, the functionality has not changed in CF11. You're simply a victim of circumstance in that you upgraded to CF11 at the same time Microsoft decided to patch Excel and cause the exact behavior you're describing. The best part...they did this on purpose!
Here is their official blog where they "apologize" for this behavior.
Upon reviewing the blog while writing this reponse it looks like they've actually released some fixes if you scroll to the bottom of the blog.
So, your users can install the fix or there are a couple ways to allow the download in Excel:
- Open Excel. Go to File-->Options --> Trust Center --> Trust Center Settings --> Protected View --> Uncheck "Enable Protected View for files originating from the Internet" check box.
- OR....Open your Windows Control Panel and open Internet Options-->Security tab-->Single click the Trusted Sites icon-->Sites button-->type: >Add button-->Close-->OK
Or, so I have been told by my developers, use the cfspreadsheet tag.
CFSpreadsheet will give same results. Blank Excel file.
It's an MS issue. Not CF. Not CF code.
We fell prey to this, as well. MS elevating the threshold for excel files, with no notice, was bad form.