Just the other night my wife was on the phone with a client who had e-mailed her a file to review. He knew we were on macs and he was on a mac so, no problem reading the file, right? Not so much.
He had created a table in Pages, but my wife doesn't have Pages on her iMac. No problem. I fired up my iMac which has Pages installed, only to get an error message indicating that I don't have the most current version and can't open the file. Ugh!