WordPress controls what filetypes are allow. If you are running Multisite is is pretty easy check this link out.
http://premium.wpmudev.org/blog/how-to-change-the-allowed-file-upload-types-in-wordpress-multisite/
On a regular site it is a little more difficult check this link out:
http://howto.blbosti.com/2010/03/wordpress-modify-the-upload-list-of-allowed-file-types/
That being said I think I will add a allowed filetypes feature to my feature request list.
Also I found a plugin today that will allow you to manage your file types try this out.
https://wordpress.org/plugins/manage-upload-types/
I appreciate your prompt attention to this. I am continuing to receive the following error at http://fywp.emuenglish.org/?page_id=207, unfortunately:
Memphis Error: Sorry, this file type is not permitted for security reasons, contact your administrator for more details.
If you are running Multisite you can add this file type from the Settings menu of the Network Admin.
I have confirmed that I am not running multisite. The plugin is updated. I can see the selectable (or deletable) filetypes listed in the settings tab, and xls is among them. I have also tried to upload the file as media, and WordPress accepts it. I can upload a .xlsx file, but I have tried to run it with a couple of different .xls files, and the error returns. I also tested it from different user accounts with no luck.
Hi,
Could you tell me the os and browser you are using do I can run some tests
Yes, sorry about that. I’m using Chrome 35.0.1916.153 on Mac OS X 10.9.4.
Problem should be solved with version 2.6.1 try it out.
Yes, it works. Thanks for the prompt follow-up!
Good to hear!! I will mark this issue as resolved then.
Cheers!!