Agenda has stopped

Quando clico no botão da câmera, aparece essa mensagem, o que pode ser?

FormularioActivity

 Button botaoFoto = (Button) findViewById(R.id.formulario_botao_foto);
        botaoFoto.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                Intent intentCamera = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
                String caminhoFoto = getExternalFilesDir(null) + "/"+ System.currentTimeMillis() +".jpg";
                File arquivoFoto = new File(caminhoFoto);
                intentCamera.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(arquivoFoto));
                startActivity(intentCamera);
            }
        });

activity_formulario.xml

<Button
                android:id="@+id/formulario_botao_foto"
                android:layout_width="56dp"
                android:layout_height="56dp"
                android:background="@drawable/camera"
                android:layout_alignParentBottom="true"
                android:layout_alignParentRight="true"
                android:layout_marginRight="16dp"
                android:layout_marginBottom="16dp" />