# Missing required source files for OnlineSubsystemEOS GDK integration (UE 5.3) 

**URL:** <https://forums.unrealengine.com/t/missing-required-source-files-for-onlinesubsystemeos-gdk-integration-ue-5-3/2684207>\
**Category:** Getting Started & Setup\
**Tags:** unreal-engine, Xbox, Blueprint, question, epic-for-indies\
**Created:** [December 11, 2025, 4:24pm UTC](https://forums.unrealengine.com/t/missing-required-source-files-for-onlinesubsystemeos-gdk-integration-ue-5-3/2684207 "2025-12-11T16:24:36Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![snipert79](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@snipert79](https://forums.unrealengine.com/u/snipert79)\
**Post date:** [December 11, 2025, 4:24pm UTC](https://forums.unrealengine.com/t/missing-required-source-files-for-onlinesubsystemeos-gdk-integration-ue-5-3/2684207/1 "2025-12-11T16:24:36Z")

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I am developing an Unreal Engine 5.3 project that integrates GDK and EOS (just) for matchmaking functionalities. I am using the source build of UE 5.3 from GitHub and have installed the Microsoft GDK (Version 230305) and the GDK Extensions for UE.

When compiling the project via Quick Launch for the GDK platform (XSX/WinGDK), the build fails within the `OnlineSubsystemEOS` plugin with the following error:

`fatal error C1083: Datei (Include) kann nicht geöffnet werden: "WinGDKEOSHelpers.h": No such file or directory`

I have verified that this file is not physically present in my GDK Extensions ZIP or the Microsoft GDK SDK installation path. I ran `Setup.bat` multiple times, but the file is not downloaded.

My Epic account has verified console access.

**Does someone knows, where the required source file `WinGDKEOSHelpers.h` should be located or how I can obtain it?**

Thank you for your assistance.