Error at Launch: Failed to load asset class when running my own unreal project

[sandyUni]

System Environment

Operating System: Windows 10 64bit 1909
Visual Studio version: 2019, 16.5.4
Unreal Engine version: 4.24.3
Airsim version: release 1.3.1
CMake version: 3.17.0

What happened:

When Launching my own unreal project, it prompts that "Failed to load asset class - Class'/AirSim/VehicleAdv/SUV/SuvCarPawn.SuvCarPawn_C'" :

Detailed Description

I am following the official tutorial to build my own unreal environment. I can't find Landscape Mountains in Learn tab of Epic Game Launcher so I create a new unreal project in unreal engine with the template Archvis:

I delete all unrelated components, then the world outliner looks like this:

I carefully follow the instruction in the tutorial, the codes in Visual Studio are compiled correctly, except for some warnings:

1>UnrealBuildTool : warning : Library 'Shell32.lib' was not resolvable to a file when used in Module 'AirSim', assuming it is a filename and will search library paths for it. This is slow and dependency checking will not work for it. Please update reference to be fully qualified alternatively use PublicSystemLibraryPaths if you do intended to use this slow path to suppress this warning.
1>UnrealBuildTool : warning : Library 'dinput8.lib' was not resolvable to a file when used in Module 'AirSim', assuming it is a filename and will search library paths for it. This is slow and dependency checking will not work for it. Please update reference to be fully qualified alternatively use PublicSystemLibraryPaths if you do intended to use this slow path to suppress this warning.
1>UnrealBuildTool : warning : Library 'dxguid.lib' was not resolvable to a file when used in Module 'AirSim', assuming it is a filename and will search library paths for it. This is slow and dependency checking will not work for it. Please update reference to be fully qualified alternatively use PublicSystemLibraryPaths if you do intended to use this slow path to suppress this warning.

which are also shown in the Airsim's default unreal project Block, so I ignore these warnings.

Then I start the game by pressing Launch button in Unreal Editor. At the startup menu, it pops up the above message, i.e., "Failed to load asset class - Class'/AirSim/VehicleAdv/SUV/SuvCarPawn.SuvCarPawn_C'".
This following picture is the logging output screen:

Other Attempts

1. The default Unreal project Block runs successfully following the same tutorial.
2. I also tried using a quadrotor instead of a vehicle, but it pops up a similar error as follows:
   
3. I tried to check the option Enable on the fly in Launch panel, surprisingly it runs correctly.
4. I press the Play button, it also runs correctly.

[sandyUni]

Finally, I addressed this issue by following the solution in #1310. However, I should also manually copy Airsim .umap file to the content folder.

[Ckq-Sugar]

@lj8385174 Hello, I also stuck at starting playing. The issue in #1310 is about packaging. Could you tell me some details about solving the problem? Thanks.

[sandyUni]

@lj8385174 Hello, I also stuck at starting playing. The issue in #1310 is about packaging. Could you tell me some details about solving the problem? Thanks.

My problem is stuck in packaging, not playing 😀. So I may not have the experience to help you.

[sandyUni]

@Ckq-Sugar I recently experienced the same error, while I used build.cmd --no-full-poly-car to build Airsim. After removing this argument, it can run correctly.