Passbook generates PKPass error

I add passbook in my app, when the system is iOS6.0 it work correctly.When the system is iOS7.1 it appear an error.

I check the code found that

PKPass *newPass = [[PKPass alloc] initWithData:passData error:&error];

When generate PKPass in iOS6.0 get a correct PKPass,when the system is iOS7.1 get a nil.

The error contain message is that:

Error Domain=PKPassKitErrorDomain Code=1 "The pass cannot be read because it isn’t valid." UserInfo=0x175cd2f0 {NSUnderlyingError=0x175c2c10 "more than one field has the key 'phone'. Field keys must be unique.", NSLocalizedDescription=The pass cannot be read because it isn’t valid.}

The data of the passbook i get it from server.Code like follow

- (void) connection:(NSURLConnection *)connection didReceiveData:(NSData *)data{
[self.connectionData appendData:data];
}

After get the data write to file,code like follow:

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask,YES);
NSString* filePath  = [[paths objectAtIndex:0] stringByAppendingPathComponent:@"pk.pkpass"];

if ([self.connectionData writeToFile:filePath atomically:YES]) {

    if (![PKPassLibrary isPassLibraryAvailable]) {

        UIAlertView *alert=[[UIAlertView alloc]initWithTitle:@"Error"
                                                     message:@"PassKit not available"
                                                    delegate:nil
                                           cancelButtonTitle:@"Pitty"
                                           otherButtonTitles:nil];
        [alert show];
        [alert release];

        return;
    }
}

After write to file i want to show it,code like follow:

    NSString* passFile = [[NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask,YES) objectAtIndex:0] stringByAppendingPathComponent:name];

NSString * newPassStr = [[NSString alloc] initWithContentsOfFile:passFile encoding:NSUTF8StringEncoding error:nil];

NSData *passData = [NSData dataWithContentsOfFile:passFile];

NSError* error = nil;
PKPass *newPass = [[PKPass alloc] initWithData:passData error:&error];

Then when i get the PKPass *newPass appear the error in iOS7.1. In iOS6 it's OK.

Anyone can tell me the reason?A lot of thanks.