need a newer version of keynote

For some reason I can't open any of my keynote presentations. Every time i try to open the file it tells me i need a newer version of keynote. I have the latest version (6.5.3)- there are no available updates on the app store, and I don't have an older version kicking around somewhere (brand new computer!) I don't know what to do and i desperately need access to this content for work. Any ideas? I've tried uninstalling and reinstalling and I'm not sure what is going on?