Logic Pro 9 Update 9.1.8: [work] Download

This happens if you try to run 9.1.8 on OS X 10.10 (Yosemite) or later. Apple never patched this because Logic Pro X was out. The solution is to turn off "Automatic Graphics Switching" in System Preferences > Energy Saver. If that fails, you must downgrade your OS to Mountain Lion or Mavericks.

If you have the original Logic Studio 9 box set (those silver DVDs), you can install the base 9.0.0 version. However, Apple no longer hosts the 9.1.8 combo updater on their main site. You must rely on Apple’s deprecated support FTP mirrors or trusted archival sites (exercise caution). logic pro 9 update 9.1.8 download

If you purchased Logic Pro 9 through the Mac App Store rather than the physical "Logic Studio" boxed set, you must update through the tab in the Mac App Store rather than using a manual .dmg installer. Fixing "Update Not Found": This happens if you try to run 9