Why can't I open my Pages doc on my desktop?

Take a look at this forum thread and see if it's the case for you.

https://discussions.apple.com/thread/6002711?answerId=25189133022#25189133022

Well the new Pages.app should be in the /Applications folder. The '09 version should have been moved to the /Applications/iWork '09 folder. You need to decide which version you want to use. The new version has had a large number of features removed and has also introduced some new bugs. The '09 version is therefore more feature-rich and more stable. If you want to stay with the '09 version you can move the Pages.app file in /Applications to another folder for safe keeping and then move the older version in /Applications/iWork '09 to /Applications. Or you could leave the application files where they are and point to one or both via the Dock.

So, first you should verify that you do indeed have both versions and if so, then you'll need to decide which one you would like to use. There are multiple threads concerning this subject, many with comments about how and why you would use one version over the other. And some folks use both.

You have 2 versions of Pages (or Numbers, or Keynote) on your Mac.

Pages 5 is in your Applications folder.

Pages '09/'08 is in your Applications/iWork folder.

You are alternately opening the wrong versions.

Pages '09/'08 can not open Pages 5 files and you will get the warning that you need a newer version.

Pages 5/5.01 can not open Pages 5.1 files and you will get the warning that you need a newer version.

Pages 5.1 sometimes can not open its own files and you will get the warning that you need a newer version.

Pages 5 can open Pages '09 files but may damage/alter them. It can not open Pages '08 files at all.

Once opened and saved in Pages 5 the Pages '09 files can not be opened in Pages '09.

Anything that is saved to iCloud is also converted to Pages 5 files.

All Pages files no matter what version and incompatibility have the same extension .pages.

Pages 5 files are now only compatible with themselves on a very restricted set of hardware, software and Operating Systems and will not transfer correctly on any other server software than iCloud.

Apple has not only managed to confuse all its users, but also itself.

Note: Apple has removed over 100 features from Pages 5 and added many bugs:

http://www.freeforum101.com/iworktipsntrick/viewforum.php?f=22&sid=3527487677f0c 6fa05b6297cd00f8eb9&mforum=iworktipsntrick

Archive/trash Pages 5, after exporting all Pages 5 files to Pages '09 or Word .docx, and rate/review it in the App Store.

Peter