CBPeripheralManager is not powered on

I keep getting an error saying my CBPeripheralManager is not powered on but in my code i feel that i carried this out. Here is my code:

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    // Start up the CBPeripheralManager
    _peripheralManager = [[CBPeripheralManager alloc] initWithDelegate:self queue:nil];
    // Start up the CBCentralManager

    // And somewhere to store the incoming data
    _data = [[NSMutableData alloc] init];
}

/** Required protocol method.  A full app should take care of all the possible states,
 *  but we're just waiting for  to know when the CBPeripheralManager is ready
 */
- (void)peripheralManagerDidUpdateState:(CBPeripheralManager *)peripheral {

    if (peripheral.state == CBPeripheralManagerStatePoweredOn) {

        // We're in CBPeripheralManagerStatePoweredOn state...
        NSLog(@"self.peripheralManager powered on.");

        // ... so build our service.

        // Then the service
        CBMutableService *transferService = [[CBMutableService alloc] initWithType:[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID] primary:YES];

        // And add it to the peripheral manager
        [self.peripheralManager addService:transferService];
    }
}

Then later I call my peripheral to start advertising with an IBAction button:

- (IBAction)advertise:(id)sender {
    [self.peripheralManager startAdvertising:@{ CBAdvertisementDataServiceUUIDsKey : @[[CBUUID UUIDWithString:TRANSFER_SERVICE_UUID]] }];
    [self.peripheralManager startAdvertising:@{ CBAdvertisementDataTxPowerLevelKey : @(YES)}];
}