When opening a Keynote presentation created on my iPad2 on my iMac, I get this error "You need a newer version of Keynote to open this presentation." When I go to the App store, there is no update available. So after learning that I can't update, I've tried to repurchase and I get "We could not complete your purchase." becaise it's already installed. I am then redirected to choose software update from the Apple Menu. Software Update returns me to the App Store and that no updates are available.
OK but I was trying to bypass the app store and use Software Download, did it redirect you to the app store?
Try this which sorts out recent issues:
delete keynote from applications folder
delete the file: .com.apple.iwork.Keynote.plist from: users > home > library > preferences
shut down the mac
restart and press shift key imediatly after the chime sound
keep shift pressed until the apple logo appears
let the mac run while on the gray screen it is repairing the software and will take 10 mins or so
when the desktop appears go to applications > utilities > disc utility > first aid and repair permissions