NSDictionary上的SIG_ABRT错误？

Question

运行我的应用程序时出现SIG_ABRT错误，并突出显示此行

NSDictionary *songInfo = [[NSDictionary alloc] initWithObjects:propertyValues forKeys:propertyKeys];

propertyValues和propertyKeys初始化几行：

NSArray *propertyKeys = [[NSArray alloc] initWithObjects:songKey, albumKey, artistKey, artistIDKey,lastPlayedKey, genreKey, ratingKey, playCountKey, nil];
NSArray *propertyValues = [[NSArray alloc] initWithObjects:songTitle, albumName, artistName, artistID,lastPlayed, genre, userRating, playCount, nil];

导致此错误的原因是什么？某些值/键是否未初始化？