So I was having some trouble connecting my BlackBerry to my Mac.
Problem 1. The BlackBerry was not even being detected by the Mac.
Solution 1. I updated the BlackBerry desktop software and all was fine.
Then came problem 2. My device password was not being accepted by the BlackBerry desktop software.
The device password for BlackBerry is determined by the text that you typed into your phone when you set your password. Even if you think you were typing in numbers.
So, for example, if you thought your password was '1234' then it is *actually* 'wers' that you need to type on your Mac/PC to connect to your BlackBerry using the desktop software.