Welcome to Justanswer.com, my name is Dustin.I'm sorry to hear about the issue you are having, I will do my best to help you resolve it.
The updater will only work if you have one of these programs installed on your mac currently
Digital Photo Professional- EOS Viewer Utility- File Viewer Utility- RAW Image Task
Also, this may not be an issue with missing a program. If your mac cannot read the sd card, t hen the sd card probably is not formatted in a mac friendly format.
So let me ask you this.. When you insert the SD card and then open the disk utility app, does disk utility show the sd card on the left listed with your other hard drives?
To g et to the disk utility app, open spotlight or click the magnifying glass, then type in disk utility
then double click the disk utility application. Now on the left side of disk utility with the SD card inserted, what drives do we see listed?
It sounds like either the SD card was formatted for windows and not a mac compatible format.
Or, the sd card itself has failed. Do you have a windows PC you have access to by chance? If not, you may want to consider a new sd card, format it in your mac first.
Then, use it in the camera. And then the mac would be able to read it.
You can get a 32gb SD card fore 10$ here, to test that theory.. http://amzn.to/2e4Uh9I