Why can't I edit some Excel files?

[Doctor_Who]

I've downloaded an Excel spreadsheet from Microsoft's Office online website, and then put it onto my OneDrive account, so that I could have access to it both from my Windows Phone (Lumia 928) and my Windows 8.1 desktop and laptop. I can easily edit it from either the desktop or laptop. But on my Lumia 928 all I can do is look at it.

Why can't I edit it?

 

[tgp]

Is it an .xls or .xlsx? You can't edit .xls on WP.

 

[vinscg]

Open it with office online... Edit something... It will auto-save
Then open on your phone, refresh, it will work.

 

[vinscg]

And only .xls office2003 is supported i think... Save as .xls (2003)