Segmentation fault when I try to create a custom sensor from PostprocessMaterial

[23wjj]

I want to create a custom camera sensor for carla simulator to render albedo(diffuse) of the image. So I create a Postprocess Material AlbedoEffectMaterial.uasset and place it under the folder Plugins/Content/PostProcessingMaterials as the following picture.

The postprocess material is:

To make the blueprints binary know this kind of material, I create a class of camera just like the official depth camera.
The code is as following:
AlbedoCamera.cpp

// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
// de Barcelona (UAB).
//
// This work is licensed under the terms of the MIT license.
// For a copy, see <https://opensource.org/licenses/MIT>.

#include "Carla.h"
#include "Carla/Sensor/AlbedoCamera.h"
#include "Carla/Actor/ActorBlueprintFunctionLibrary.h"

#include "Carla/Sensor/PixelReader.h"

FActorDefinition AAlbedoCamera::GetSensorDefinition()
{
  return UActorBlueprintFunctionLibrary::MakeCameraDefinition(TEXT("albedo"));
}

AAlbedoCamera::AAlbedoCamera(const FObjectInitializer &ObjectInitializer)
  : Super(ObjectInitializer)
{
  AddPostProcessingMaterial(
      TEXT("Material'/Carla/PostProcessingMaterials/PhysicLensDistortion.PhysicLensDistortion'"));
  AddPostProcessingMaterial(
      TEXT("Material'/Carla/PostProcessingMaterials/AlbedoEffectMaterial.AlbedoEffectMaterial'"));
}

void AAlbedoCamera::PostPhysTick(UWorld *World, ELevelTick TickType, float DeltaSeconds)
{
  TRACE_CPUPROFILER_EVENT_SCOPE(AAlbedoCamera::PostPhysTick);
  FPixelReader::SendPixelsInRenderThread(*this);
}

And AlbedoCamera.h

// Copyright (c) 2017 Computer Vision Center (CVC) at the Universitat Autonoma
// de Barcelona (UAB).
//
// This work is licensed under the terms of the MIT license.
// For a copy, see <https://opensource.org/licenses/MIT>.

#pragma once

#include "Carla/Sensor/ShaderBasedSensor.h"

#include "Carla/Actor/ActorDefinition.h"

#include "AlbedoCamera.generated.h"

/// Sensor that produces "albedo" images.
UCLASS()
class CARLA_API AAlbedoCamera : public AShaderBasedSensor
{
  GENERATED_BODY()

public:

  static FActorDefinition GetSensorDefinition();

  AAlbedoCamera(const FObjectInitializer &ObjectInitializer);

protected:

  void PostPhysTick(UWorld *World, ELevelTick TickType, float DeltaSeconds) override;
};

And these two files are put under the same folder of other camera sensors.
To serialize the new kind of camera, I bind it with the pre-complemented s11n::ImageSerializer like following:
std::pair<AAlbedoCamera *, s11n::ImageSerializer>, in the file LibCarla/source/carla/sensor/SensorRegistry.h.
And I remake the whole carla from source code, and launch the UEEditor succesfully.
But when I want to control the vehicle through pygame widget, and render the images through this sensor.camera.albedo, I got segmentation fault(core dumped).

camera_bp = self.world.get_blueprint_library().find('sensor.camera.albedo')
disp_size = self.display_man.get_display_size()
camera_bp.set_attribute('image_size_x', str(disp_size[0]))
camera_bp.set_attribute('image_size_y', str(disp_size[1]))
camera_bp.set_attribute('fov', str(120))
camera_bp.set_attribute('sensor_tick', str(0))
camera = self.world.spawn_actor(camera_bp, transform, attach_to=attached)
camera.listen(self.save_rgb_image)

I guess the problem may comes from the serialization part or the prostprocess material but I'm not quite sure. Can someone kindly helps me? Thanks a lot!
And I've checked the blueprints binary has keyword "sensor.camera.albedo" in it.