Pages 5 document will no longer open in pages 5

Question

I upgraded to Mavericks a few days ago and afterwards, I had both Pages '09 and Pages 5 in my dock, instead of one of them being in the applications folder. They are both still in my dock. I have looked briefly at Pages 5 and determined that, at this time, I prefer Pages '09. All of my documents were created in Pages '09 and now they will no longer open in Pages '09. (Some will, and I don't know what the difference is between the ones that will and the ones that won't) When I try to open one, it either opens, no problem, or I get the message "The required index.xml file is missing." This message is in a rectangle with an icon representative of Pages '09 (the inkwell). Since it has this icon, I'm assuming that I was trying to open it in the Pages '09 version, which is what I intended o do. Since this didn't work, I tried to right click and "Open with Pages.app (4.0.5)" and got the same message. I was a little afraid to try to open it in Pages 5, since I've heard rumors that this could ruin the document. I would like to be able to use either of the apps but, since I apparently can't do that, I gathered my courage and opened a document in Pages 5. Everything seemed to be okay, so I opened a couple more. One of them, I even was able to edit with no problem. But when I tried to open it again hours later, I got an error message saying ". . . can't be opened because it is from an "unidentified developer". What's going on here? The only people involved in this document are Apple and me. What "unidentified developer" are they talking about? And why was it fine, then a few hours later it was not accessible? If I'm forced to use only Pages 5, I guess I can live with that, but it seems as though I will have to live in constant fear that, at any time, my document will not open. I've read about a lot of other people who are having problems, too, but not this particular one. I'm at a loss and, like everybody else, I have important documents that I need access to. I'm using an iMac and 10.9.4. What to do?? I need my stuff!

Answer 1

1. You have allowed Apple to auto-upgrade your Mac
Turn off auto-update here:
Menu > Apple > System Preferences > App Store
2. The Icons on your dock are Aliases not real apps
They point to where the apps really are which is:
For Pages 5.2.2 in your Applications folder
For Pages '09 in your Applications/iWork folder
3. You are alternately opening documents randomly with either version of Pages
Both Pages have the same file extension .pages and there is no certainty as to which version opens them when you double click on a file.
right click on the file and choose which version you want to open it
4. Pages '09 can not open Pages 5 files
Pages 5 can not open Pages '08 files, and will convert and change Pages '09 and Word files.
It will also auto save opened files into its own format.
You can export these back to Pages '09 if you need to:
Menu > File > Export > Pages '09
5. Yes Pages 5.2.2 is a marked downgrade
Pages 5.2.2 has a few improvements but has had over 110 features removed and is buggy.
Sooner or later you will not be able to open a file or have it damaged in some way and it has a complex obscure file format largely incompatible with everything else, so you will not be able to rescue the contents of your file. If Pages or some third party server/eMail don't trash your file, eventually Apple will do it for you as it did when it released Pages 5 last September. I recommend using Pages '09 for the time being whilst you look for viable alternatives, some are here already and some are on the way.
For further information about what has happened:
http://www.freeforum101.com/iworktipsntrick/viewforum.php?f=22&sid=0882463378700 abf43a0f2433506bbbc&mforum=iworktipsntrick
Peter