Hi Eugenied,
I'd like to tell you that trial version for Parallels Desktop 9 is no longer available. We only have a trial version for Parallels Desktop 11 with us as it is the latest product.
You can either try to upgrade your Mac's operating system to 10.9.5 or above or you can try to Purchase Parallels Desktop 9 from authorized re-sellers like Amazon.com, Bestbuy.com, etc.