Customize Scene with Unreal Engine failed in R2020b

Back in MATLAB R2020a, I was able to follow the guide at https://www.mathworks.com/help/driving/ug/customize-scenes-using-simulink-and-unreal-editor.html to get my vehicle simulation to work with a 3D scene created by modification from an existing AutoVrtlEnv project level. Now I cannot seem to do the same thing with the newly shipped MATLAB R2020b. There's something not right. Tried the guide on both my Windows PCs, didn't work, need some help.

After click RUN in my Simulink model, and click PLAY in the UE4 editor, I got static image in UE4 window, and black screen on the 3D Camera Read block popped up window. The diagnostic viewer throws repretead warning message below:

> In sim3d/CameraReader/read

In sim3d/AbstractCameraSensor/read

In Simulation3DVisionSensor/stepImpl

Warning: The block 'DriftDemoBicycle/3D Visualization/Simulation 3D Camera Get/Simulation 3D Camera Read' returned no data (error code: -1). Make sure that the block sample time is greater than the Simulation 3D Scene Configuration block sample time.

[Tong Zhao]

Just to add to the above failure, if I first package the customized scene then use the Simulation 3D Scene Configuration block to specify the packaged executable, Simulink doesn't seem to recognize the newly packaged scene but provides a warning:

This means that the packaged scene (named "CircleTrack") wasn't recognized. And another thing observed in UE4 is that, all the pre-built scens have a Data Asset object alongside the Level map, but my customized scene doesn't have it, and I don't know if or how to create that Data Asset object for my customized scene:

I think missing the Data Asset object might be connected to both the failures (either in Unreal Editor mode, or in packaged executable form). If I right click on any of the Data Assets under Content/Maps folder, it points to the C++ file PrimaryAssetLabel.h, which is non-existing in the AutoVrtlEnv project.

So if someone knows how to create this Data Asset, it might solve my problem. Thanks for any hint.