I'm currently on a PowerBook5,8 1.67GHz running Leopard 10.5.8 having recently done a clean install from OS Tiger. I also installed Leopard Rebirth so the About This Mac shows Sierra 10.12.4. Also have TTF FPR5 installed which so far runs well. My problem is to get MacTracker to run. I first downloaded MacTracker 7.4.1 for Leopard. It installed ok but wouldn`t open. Tried several more times - each failed. Removed the app and dependents using AppCleaner. Downloaded same several days later, and installed. Same problem, it won't run and met with this message: Any ideas anyone?