I am not running 10.7.5.
Yes, but what is it? Newer or older than 10.7.5? This is essential to find out, if you can install the version sold at the appStore on your MBP. If you are running an earlier version of Mac OS X on your MBP, you cannot download Aperture from the Mac App Store (MAS) to your MBP, because at least 10.7.5 is required.
Again my question - where exactly did you download from, if you are running a downloaded version of Aperture:
- From the Mac App Store (MAS),
- or from the earlier Apple Store?
If you downloaded from the Apple Store, you should have received a serial number. Then you can download an Aperture installer (the Trial version) online from Aperture 3.1 Trial and unlock it with your serial number. You can see the serial number, if your Aperture version has one, in the about panel. Select the menu entry "Aperture > About Aperture". If you see a serial number, you bought from the Apple Store, and you can download an installer here:
Aperture 3.1 Trial
This will accept the serial number you see on your iMac, if that version has a serial number.
If you downloaded from the App Store, you cannot install the version you purchased, unless you are running 10.7.5 or later on your MBP.
Regards
Léonie