UE 5.3 - Cannot Build Project [cannot open include file]

Development Programming & Scripting C++
1

Dear community,

Please help me about the issue while building UE 5.3 project.

I’ll try to explain the problem and what I’ve tried in below.

  1. I install the UE 5.3 via Epic Games Launcher. (Windows 11)

  2. Launch the engine and created a simple C++ based ThirdPerson project.

  3. It gives an error just after the project creation as below

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    image2432×539 79.1 KB

  4. I tried to build in Visual Studio but it gives the same error

  5. I’ve deleted Intermediate and Binaries folder and generate the VS files manually. Then I tried to build the project but it gave same error.

    image
    image1792×358 48 KB

  6. I checked where this file is included, and find out it’s engine class called “CoreNetTypes” which placed in “Engine/Source/Runtime/CoreUObject/Public/UObject/CoreNetTypes.h”

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    image1078×360 27.5 KB

  7. I checked related include folder under Engine/Intermediate folder as below, and it’s there. I didn’t understand how this file couldn’t be found while building.

    image
    image1097×218 8.33 KB

  8. Then I checked VC++ Include Directories as below for both Engine and Game project in Visual Studio.
    image

  1. I’ve checked platform SDKs in Unreal Engine 5.3 Release Notes, and I’m sure that everything is correct.
    image

  2. This is the project directory, I don’t see problem with folder names etc.
    “B:\UNREAL PROJECTS\Test\Test53UE”

NOW…

I don’t know what to do, and really want to use newest version of the engine.
Please share your comments, correct me if I checked the wrong things etc.

2

I’m having the same issue and nothing worked out. -_-

3

Just remove the BuildConfiguration.xml at
C:\Users@Your Username@\AppData\Roaming\Unreal Engine\UnrealBuildTool
And it will build

2 Likes
4

Hey @Shawntane

It worked! Thank you so much, you saved the day!

1 Like
5

This not working when compile bins with -DisableUnity parameter with empty c++ project

"{ENGINE_PATH}\Engine\Build\BatchFiles\Build.bat" "{PROJECT_PATH}\MyProject.uproject" MyProjectEditor Win64 DebugGame -DisableUnity
6

My old build configuration xml file also contains “bUseUnityBuild: false”, maybe 5.3 forces to use unity build somehow.

7

Deleting the build configuration did not help, the steps I took to achieve this error is.

Download fresh unreal 5.3
create new empty c++ project
error happens

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image1542×458 54.8 KB

Enyone have another solution?

8

Same problem here. Creating c++ project with 5.1 works fine and i can build successfully. But on 5.3 i get the exact same error. Tried to unistall everything and have only 5.3 too but nothing worked.

9

Workaround: add MinSourceFilesForUnityBuildOverride = 1 to each *.Build.cs of your project, because this error only with non-unity build

10

I had missed a build configuration file. deleting all build configuration files worked.

For all locations see: Build Configuration | Unreal Engine Documentation

1 Like
11

Thanks brother! Deleting an old configuration file from Documents fixed the issue

12

Fixed by cherrypicking commit b0b17403e5a11b7b59dcf5168f40f9987340f595 to fix compilation non-unity into your custom engine from branch 5.3. In 5.4 this error will no longer exist

1 Like