What is PPDG?
PPDG is short for Premiere Pro Down Grader. It removes a particular limitation of the .prproj file format: its lack of backward compatibility.
As an editor, you may be avoiding the newest version of Adobe Premiere Pro CC because of bugs that are currently not ironed out. But perhaps you started a project on a newer version not realizing how buggy it is and want to go back to a stable version.
If this is you, PPDG may be of use. PPDG allows you to open project files authored on newer versions of Premiere even if you don't have the latest version running. This may save the day or it may cause Premiere to crash. If you utilized features unique to that newer version in your project, your results may be less than optimal. The one advantage of using PPDG over the handful of online PP downgraders is that there is no size limit on project files.
USE AT YOUR OWN RISK.
Requires: macOS 10.8 and later
UPDATE 2: The downgraded previous project files PPDG creates may not always work. The biggest factor appears to be how many version numbers your copy of Premiere is away from the version the .prproj file was created with.
UPDATE 1: Well, Apple being Apple, they have made it pretty hard to distribute home-brew software. I am making zero dollars from this software so it makes little sense for me to pay Apple's $100 developer account fee in order to notarize my apps. This means that:
If PPDG refuses to run at all (giving you an alert box instead), or it runs but puts up an error instead of converting your project, your copy of PPDG may have been “quarantined” by the OS. If you’d like to fix this, and you feel comfortable bypassing the OS security, try the following:
Go to: https://github.com/alienator88/Sentinel/releases and download Sentinel. This is a Mac application that allows you to launch unsigned apps. This can be very dangerous if you are launching an unsigned app that is malicious. PPDG is not, but just a heads up.
After it is removed from quarantine with Sentinel, PPDG should operate normally now.