The excel files created can't be opened.

I am also facing the same problem, waiting for the answer.

Sorry for late reply.

Can you please tell me which operating system and browser you are using.

No worries Kapil. I am on Windows 8, Firefox is the browser.

One more thing:

Which version of MS office you are using?

MS office 2010

I have checked it but didn’t find any issue.

Have you given any blog name to your site. It would be great if you can share a screenshot of error along with URL.

I am on a Mac with OS X Yosemite 10.10.1 using Numbers to open the file.

This is my site : https://studentaffairscollective.org
This is the screenshot of error I am getting on .xlsx file : https://screencast.com/t/LQ4YYQE89lUv
screenshot of error I am getting on .xls file : https://screencast.com/t/T5cPbRiKsvIZ

Yes, it is not working with xlsx extension but xls is opening if you ignore error.

Will find a solution soon and get back to you.

Sorry for the inconvenience caused.

No problem,

Let me know whenever you fix the problem.

Regards,
JC