The problem: I had Hazel set to add mp3 files to a certain playlist in iTunes. At some point, it stopped working: the songs would be added to iTunes, but not to the playlist. The logs showed this error message:
2009-11-18 13:21:38.410 hazelfolderwatch[9323] iTunes import error: {
NSLocalizedDescription = "iTunes got an error: File permission error.";
NSLocalizedFailureReason = "File permission error.";
OSAScriptErrorAppAddressKey = <NSAppleEventDescriptor: 'psn '("iTunes")>;
OSAScriptErrorAppNameKey = iTunes;
OSAScriptErrorBriefMessageKey = "File permission error.";
OSAScriptErrorMessageKey = "iTunes got an error: File permission error.";
OSAScriptErrorNumberKey = -54;
OSAScriptErrorRangeKey = NSRange: {0, 0};
Diagnosis: Eventually, I discovered that this happened because I have two playlists with the same name—one a regular playlist and one a Smart Playlist. Maybe Hazel was trying to add the files to the Smart Playlist....
Anyway, renaming the Smart Playlist solved the problem. But it would be helpful if Hazel could check for this situation and prefer the non-smart playlist. Even a more descriptive error message, such as 'Hazel can't add files to Smart Playlists,' would have helped me troubleshoot this more quickly.
By the way, thanks for Hazel—it's a great program.