I have an older version of Pro Tools that requires Mac OS v10.7+ but isn't capable of understanding x.10 is higher than x.7.
Therefore, the only thing left to do is buy a new copy (no) or change the Operating System's version number. Here's how:
Step 1 - Disable System Integrity Protection
A. Restart your Mac and boot it in recovery mode by holding down
B. Open up Terminal and type
C. Restart the computer.
Step 2 - Modify your Mac's version number
A. First things first, let's create a backup:
sudo cp /System/Library/CoreServices/SystemVersion.plist ~/SystemVersion.plist.bak
B. Open up SystemVersion.plist using
nano and set it to write mode.
nano -W /System/Library/CoreServices/SystemVersion.plist
C. Modify these two nodes:
<plist version="1.0"> <dict> ... <key>ProductUserVisibleVersion</key> <string>10.9</string> <key>ProductVersion</key> <string>10.9</string> </dict> </plist>
D. Save your work and install Pro Tools.
E. Once you get passed the initial installer, don't forget to undo your work by repeating steps 2.b and 2.c.