Android Shipping build fails with undefined symbol: LowLevelTasks::FTask::ActiveTask (UE 5.6.1)

Development Platform & Builds
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Hi,

I’m encountering a linker error when building an Android Shipping build in Unreal Engine 5.6.1. The project builds successfully in Development and DebugGame, but fails consistently in Shipping.

Error

ld.lld: error: undefined symbol: LowLevelTasks::FTask::ActiveTask
>>> referenced by Task.h:371 (Runtime/Core/Public/Async/Fundamental/Task.h:371)

This appears multiple times from different modules:

  • CUBlueprintLibrary.cpp (SocketIOClient plugin)

  • BinkMediaTextureResource.cpp (BinkMedia plugin)

Full example:

UATHelper: Packaging (Android (ASTC)): ld.lld: error: undefined symbol: LowLevelTasks::FTask::ActiveTask
>>> referenced by Task.h:371
>>> ...CUBlueprintLibrary.cpp.o
>>> ...BinkMediaTextureResource.cpp.o
clang++: error: linker command failed with exit code 1

Build Setup

  • Engine Version: UE 5.6

  • Platform: Android (ASTC)

  • NDK: r27

  • SDK: 34

  • Build Method:
    Editor → Packaging (Shipping fails)
    Command line (RunUAT BuildCookRun) (Shipping fails)