iOS：Zombie Messaging访问NSUserDefaults时

Question

在为僵尸分析应用程序时，我收到以下错误：

堆栈：

代码：

启动应用后，我们会使用类似的代码访问多个NSUserDefaults属性。有时，应用程序会在尝试访问默认值的不同方法上崩溃。

+(NSString*)getSettingsFileName{
    prefs = [NSUserDefaults standardUserDefaults];
    return [prefs objectForKey:@"SettingsFileName"];  // EXC_BAD_ACCES (code=1, address=0x8178b6ed)
}

我尝试在访问之前同步NSUserDefaults，但我得到了相同的行为。

非常感谢有关如何解决此问题的任何提示！

修改

+(void)readSettingsDataAndUpdateIncludeDomain:(BOOL)updateDomain MBMHost:(BOOL)updateMBMHost
{
    //Read from Documents directory
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *settingsFileName = [documentsDirectory stringByAppendingPathComponent:SETTINGS_FILE];

    NSDictionary *settingsDic = nil;
    NSFileManager *fileManager = [NSFileManager defaultManager];
    BOOL fileExists = [fileManager fileExistsAtPath:settingsFileName];
    if(fileExists) {
        settingsDic = [NSDictionary dictionaryWithContentsOfFile:settingsFileName];
    } else {
        NSError *error = nil;
        NSString *settingsBundleFilePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:SETTINGS_FILE];
        BOOL success = [fileManager copyItemAtPath:settingsBundleFilePath toPath:settingsFileName error:&error];
        if(success)
            settingsDic = [NSDictionary dictionaryWithContentsOfFile:settingsFileName];
    }
    prefs = [NSUserDefaults standardUserDefaults];
    if(!fileExists)
    {
      //subscription
      [prefs setBool:YES forKey:@"Resubscribe"];
    }
    [prefs setObject:[settingsDic objectForKey:@"ADDRNAME"] forKey:@"ADDRNAME"];
    if( updateDomain )
    {
        [prefs setObject:[settingsDic objectForKey:@"Domain"] forKey:@"Domain"];
    }
    [prefs setBool:[[settingsDic objectForKey:@"Https"] boolValue] forKey:@"Https"];

    if( updateMBMHost )
    {
        [prefs setObject:[settingsDic objectForKey:@"Host"] forKey:@"Host"];
    }
    [prefs setObject:[settingsDic objectForKey:@"ServerNode"] forKey:@"ServerNode"];

    [prefs removeObjectForKey:@"ULVersion"];
    [prefs setObject:[settingsDic objectForKey:@"ULVersion"] forKey:@"ULVersion"];
forKey:@"ULDownloadOnly"];
    [prefs setObject:[settingsDic objectForKey:@"AgentName"] forKey:@"AgentName"];


    if ([[Settings getSettingsFileName] length] < 1) //This is the Line where it usually crashes"
        [prefs setObject:[settingsDic objectForKey:@"SettingsFileName"] forKey:@"SettingsFileName"];
    [prefs setObject:[settingsDic objectForKey:@"ScannerType"] forKey:@"ScannerType"];
    NSString *supportEmailAddress = [settingsDic objectForKey:@"SupportEmailAddress"];
    if( supportEmailAddress == nil )
    {
        supportEmailAddress = SUPPORT_EMAIL_ADDRESS;
    }
    [prefs setObject:supportEmailAddress forKey:@"SupportEmailAddress"];
    //Don't set SyncCalContactsMode from plist since this will overide the user's selection
    if([[settingsDic objectForKey:@"Instance"] length] > 1)
        [prefs setObject:[settingsDic objectForKey:@"Instance"] forKey:@"Instance"];
    else if ([[Settings getInstance] length] < 1) 
        [prefs setObject:@"Company" forKey:@"Instance"];

    NSString *info = [NSString stringWithFormat:@"ULVersion = %@, ULDownloadOnly = %@ ", ([Settings getULVersion]==nil)?@"Version1":[Settings getULVersion], [Settings getULDownloadOnly]?@"YES":@"NO"];

    [DebugLog writeDebugData:info];
}