AVCaptureMovieFileOutput - no active/enabled connections

I had the same problem while changing videoDevice activeFormat and later wanted to record video. Because I was using best quality video I had to set sessionPreset to high, like following

_session.sessionPreset = AVCaptureSessionPresetHigh;

and it worked for me! :)

Because currently you don't have an active connection to record video to file.
Check connection active status before recording to output file:

AVCaptureConnection *c = [self.movieOutput connectionWithMediaType:AVMediaTypeVideo];if (c.active) {  //connection is active} else {  //connection is not active  //try to change self.captureSession.sessionPreset,  //or change videoDevice.activeFormat}

If connection is not active, try to change captureSession.sessionPreset or videoDevice.activeFormat.
Repeat until you have set a valid format (that means c.active == YES). Then you can record video to output file.

Several things are missing in your code :

1. You forgot to add movieOutput to your captureSession
2. Same for your audioInput
3. All your session configuration needs to be encapsulated by [_captureSession beginConfiguration] and [_captureSession commitConfiguration]
4. For audio recording you need to set the AVAudioSession to the correct category.

Here is your code updated :

- (void)viewDidLoad{    [super viewDidLoad];    NSError *error = nil;    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryRecord                                           error:&error];    if(!error)    {        [[AVAudioSession sharedInstance] setActive:YES error:&error];        if(error) NSLog(@"Error while activating AudioSession : %@", error);    }    else    {        NSLog(@"Error while setting category of AudioSession : %@", error);    }    self.captureSession = [[AVCaptureSession alloc] init];    AVCaptureDevice *videoDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];    AVCaptureDevice *audioDevice = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeAudio];    self.videoInput = [AVCaptureDeviceInput deviceInputWithDevice:videoDevice error:nil];    self.audioInput = [[AVCaptureDeviceInput alloc] initWithDevice:audioDevice error:nil];    self.stillImageOutput = [[AVCaptureStillImageOutput alloc] init];    NSDictionary *stillImageOutputSettings = [[NSDictionary alloc] initWithObjectsAndKeys:                                              AVVideoCodecJPEG, AVVideoCodecKey, nil];    [self.stillImageOutput setOutputSettings:stillImageOutputSettings];    self.movieOutput = [[AVCaptureMovieFileOutput alloc] init];    [self.captureSession beginConfiguration];    [self.captureSession addInput:self.videoInput];    [self.captureSession addInput:self.audioInput];    [self.captureSession addOutput:self.movieOutput];    [self.captureSession addOutput:self.stillImageOutput];    [self.captureSession commitConfiguration];    AVCaptureVideoPreviewLayer *previewLayer = [AVCaptureVideoPreviewLayer layerWithSession:self.captureSession];    previewLayer.frame = CGRectMake(0, 0, 320, 500);    [self.view.layer addSublayer:previewLayer];    [self.captureSession startRunning];}- (IBAction)toggleRecording:(id)sender{    if(!self.movieOutput.isRecording)    {        [self.recordButton setTitle:@"Stop" forState:UIControlStateNormal];        NSString *outputPath = [NSTemporaryDirectory() stringByAppendingPathComponent:@"output.mp4"];        NSFileManager *manager = [[NSFileManager alloc] init];        if ([manager fileExistsAtPath:outputPath])        {            [manager removeItemAtPath:outputPath error:nil];        }        [self.movieOutput startRecordingToOutputFileURL:[NSURL fileURLWithPath:outputPath]                                      recordingDelegate:self];    }    else    {        [self.recordButton setTitle:@"Start recording" forState:UIControlStateNormal];        [self.movieOutput stopRecording];    }}- (void)captureOutput:(AVCaptureFileOutput *)captureOutput didFinishRecordingToOutputFileAtURL:(NSURL *)outputFileURL fromConnections:(NSArray *)connections error:(NSError *)error{    NSLog(@"Did finish recording, error %@ | path %@ | connections %@", error, [outputFileURL absoluteString], connections);}

Hope this helps