Hello,
Environment: Windows 11 Pro, RTX 5070 Ti 16 GB, RAM 32 GB.
An official GitHub UE 5.8.4 source build and a separate C++/Blueprint test project have passed engine build, C++ compilation, DX12/SM6 rendering and Windows Development packaging validation. There are 15 pre-existing ‘Condition failed’ startup messages whose cause remains UNKNOWN; they are not being attributed to this block.
Historical reproduction in an independent project:
- Use the UE 5.8.4 source-built UnrealEditor.exe; MetaHuman Creator Core Data is present.
- Enable MetaHumanCharacter (Creator) in that independent project’s descriptor.
- Start the Editor normally while Smart App Control is On.
- During PreLoadingScreen plugin loading, UnrealEditor-ElectraPlayerPlugin.dll fails with Win32 error 4551. The Editor reports that ElectraPlayerPlugin cannot load and requests exit.
Exact module:
C:\UE\UE_5.8.4_Source\Engine\Plugins\Media\ElectraPlayer\Binaries\Win64\UnrealEditor-ElectraPlayerPlugin.dll
SHA256 flat: C875CAB7944B97A82AAB53A3242F8F0B04BE482E793783D0D3ADE35091AC3062
Size: 57344 bytes. File version: 5.8.4. Authenticode: NotSigned; no signer certificate.
At 2026-10-22 14:11:00 KST, CodeIntegrity events 3077, 3033 and two 3089 signature records share ActivityID {1eb1cc7c-616c-0002-9196-e31e6c61dd01}.
Policy: VerifiedAndReputableDesktop, GUID {0283ac0f-fff1-49ae-ada1-8a933130cad6}.
Status: 0xC0E90002 (STATUS_SYSTEM_INTEGRITY_POLICY_VIOLATION). 3089 reports TotalSignatureCount=0 and publisher Unknown. The 3077 SHA256 Flat Hash matches the current file. The related 3076 audit count is zero for this DLL in the query window 2026-10-21 14:44:28 to 2026-10-22 14:44:28 KST. This identifies Smart App Control enforcement; it is not a Defender malware detection claim.
The existing build log records compilation/linking of this module and Result: Succeeded. Engine and plugin module manifests share BuildId 672661b7-b856-454e-bd75-f8768aabecd7. The source commit is f45729c0b6f097038e72b52d366a62baeca3275b. These local records are provenance evidence, not a malware-safety attestation.
Installed descriptor chain:
MetaHumanCharacter → MetaHuman → CaptureManagerEditor → CaptureManagerCore → ElectraPlayer.
The plugin-descriptor dependencies are enabled and non-optional for the failing Win64 Editor configuration. CaptureMetadataExtraction.Build.cs also depends on ElectraPlayerPlugin, and CaptureExtractTimecode.cpp explicitly loads it to read media frame-rate/timecode metadata.
Questions:
- Is MetaHuman Creator supported in this exact 5.8.4 source-build configuration with Smart App Control enabled? Is there a documented issue or supplier-supported correction for this module’s trust/signing state?
- Is an official precompiled 5.8.4 engine/MetaHuman distribution a supported alternative for this issue? If so, please identify the official distribution route and exact component combination.
- Is there a supported configuration that removes this dependency while preserving Creator functionality? I am not proposing forced plugin disablement or source edits.
- If an official binary is the appropriate route, which complete engine/plugin/Core Data combination should be tested separately? I will not copy an individual binary DLL into the source build or alter BuildId checks.
Current state: MetaHuman is BLOCKED. MetaHuman plugins remain disabled only in the independent CharacterLab to preserve working non-MetaHuman automation. No new character was created. Security settings, existing DLLs, engine source and certified projects remain unchanged.
I need a supported route that keeps Smart App Control, Defender and existing development projects intact. Please do not treat this as authorization to disable security or replace DLLs.
Raw logs, binaries, credentials, personal contact information and account screenshots are not attached. A sanitized minimal log extract can be prepared if requested.
Thank you.