Pages Update can't open older document

Question

Last week I updated Pages on my iPad, I am now only able to open documents that were created after the update.  When I select older documents, a window pops up and says "Document can't be imported.  The file format is invalid."

Answer 1

Try this. It worked for me.
I discovered the same problem.  I had an older version of Pages on my iPad. After updating it to the latest version all my previous documents created in pages for the iPad were rendered unreadable and a message stated that they were an invalid format.  Why for the life of me would a program that was created by Apple and sense updated not be able to read previous versions...well that's a whole other sad story.  Any way I discovered how to fix it but it would require that you had backup your iPad on a computer and not emptied your trash. If this sounds good than here is how you fix it... And it worked for me.
These steps will enable you to reinstall a previous version of the Pages app so you can be able to read and edit older documents.
FIRST: if you did backup your iPad using your computer and did not empty your trash, GOTO the trash and look for PAGES 1.4 (or other number) ipa ( that's the file extension) ie PAGES 1.4 ipa.
SECOND: move that file out of the trash and onto your desktop.  Once you do this, double click on it and a box will come up stating a newer version has been found and do you want to revert back to older version. ANSWER YES. It will than automatically place and overwrite the older version back into the file on iTunes that contains the rest of your backed up apps.
THIRD: and this is where it is important that your backup would have to have been on your computer. I'm not sure if backup on the cloud will work.  iCloud backup at your own risk And here's why. Before you restore you will need to remove the latest version of Pages off your iPad by doing the usual : holding down the home button until the apps wiggle and remove by pressing on X on app.  Removing off your iPad will also delete all your documents but if you have a previous backup on your computer those documents will be stored safely on itunes and will return.
FORTH: plug your iPad into your computer and allow it to sync so iTunes will recognize it. Once iTunes is up and you can see that it recognizes your iPad, GOTO "FILE/DEVICES/RESTORE FROM BACKUP."  ******* DO NOT CLICK ON BACKUP***** click on RESTORE FROM BACKUP. This will reinstall all previous settings and documents that were their when you backuped PLUS the older version of Pages that you placed back from the above steps. Let it run through all the setups ( this could take up to 20 minutes...depending on amount of data and photos and apps).
FIFTH: Once everything is reinstalled a message will popup on your computer stating "to leave iPad plugged in until iTunes recognizes it again" ( it's basically rebooting itself).  Once done (leave iPad plugged in still) GOTO iPad and follow the steps. IMPORTANT:  iPad will ask you if you want to SET IT UP AS A NEW IPAD, BACK UP FROM THE CLOUD or BACK UP FROM ITUNES.....press SET UP AS NEW IPAD. Follow all of the steps required. Once complete GOTO iTunes on computer, look for "IPAD" plus a little arrow ( should be on upper right corner of iTunes window, click on it ( this will safely disconnect your iPad from iTunes) . Now unplug iPad from computer and go to your iPad and look for the older version of Pages. It should be there along with all your old documents ( readable and editable too).
Hope this helps. Good luck.