[tony20970]

Hello,

I have Pro Tools 11 installed on my Mac i7 and it runs perfectly. I need plug-in compatibility between PT11 and earlier versions of Pro Tools so I downloaded my copy of Pro Tools 10.3.8 from Avid so I can have PT11 and PT10 co-installed on my Mountain Lion OS.

My mac is not connected to the internet, because I do not want any automatic updating to Mavericks OS, so I can have both versions co-installed.

However, when attempting to open "Pro_Tools_10_3_8_Installer_80777.dmg" it says the disk image could not be opened. "Reason: Not Recognized". I tried dragging the icon into the Applications folder and manually trying to "mount the image" and it is "not recognized".

What am I missing here? Any and all help is much appreciated! Thank you!!