Upgrading to High Sierra (macOS 10.13) may break Logic Pro X, Main Stage, Garage Band, or other DAWs.
Symptoms:Plugins can’t validate the license filePlugins crash or hang the DAW while scanning or loading a sessionPresets, channel strips, and templates can’t be saved or loaded
If you upgraded from Logic Pro 9 to Logic Pro X prior to the upgrade to High Sierra, chances are that your “Audio Music Apps” folder is broken.
Fix:Quit Logic Pro X, Main Stage, or Garage Band.Go to your “Music” folder in your user home. If you find an alias to “Audio Music Apps”, delete it.Create the folder “Audio Music Apps” inside “Music”, you should have this structure:
Macintosh HD / Users / “your user home” / Music / Audio Music AppsOpen Terminal (you can find it in /Applications/Utilities/) and paste this:
open /.HFS+\ Private\ Directory\ Data?/Copy/move the content you’ve found with the Terminal into the newly created “Audio Music Apps” folder.Restart your Mac just in case.