I have been experiencing crashes with the same error for a long time now. Earlier I was using UE 4.18, which was working perfectly, but suddenly this error came up. I thought downgrading the editor would help, but no.
I have tried all the given fixes given on: Unreal Engine is exiting due to D3D device being lost. (Error: 0x887A0006 - 'HUNG') - Pipeline & Plugins - Unreal Engine Forums
However these solutions are for ‘HUNG’, while mine is ‘INTERNAL_ERROR’.
My current system specs are:
Processor: Intel Core - i5 6200u 2.3~2.8GHz
Graphics Card: AMD Radeon R5-M430 2048MB
RAM: 8GB
DirectX Version: 12
To reproduce the same bug/error/crash I have to either import any one of the ‘visual effects’ mode or change the material of any product 4-5 times consecutively.
The callstack for this error is:
UE4Editor_Core!FDebug::AssertFailed() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
UE4Editor_D3D11RHI!TerminateOnDeviceRemoved() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\windows\d3d11rhi\private\d3d11util.cpp:192]
UE4Editor_D3D11RHI!VerifyD3D11Result() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\windows\d3d11rhi\private\d3d11util.cpp:231]
UE4Editor_D3D11RHI!FD3D11Viewport::PresentChecked() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\windows\d3d11rhi\private\d3d11viewport.cpp:289]
UE4Editor_D3D11RHI!FD3D11Viewport::Present() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\windows\d3d11rhi\private\d3d11viewport.cpp:472]
UE4Editor_D3D11RHI!FD3D11DynamicRHI::RHIEndDrawingViewport() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\windows\d3d11rhi\private\d3d11viewport.cpp:591]
UE4Editor_RHI!FRHICommandList::EndDrawingViewport() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\rhi\private\rhicommandlist.cpp:1399]
UE4Editor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindow_RenderThread() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\slaterhirenderer\private\slaterhirenderer.cpp:876]
UE4Editor_SlateRHIRenderer!TGraphTask > >::ExecuteTask() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\core\public\async\taskgraphinterfaces.h:784]
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\async\taskgraph.cpp:650]
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\async\taskgraph.cpp:559]
UE4Editor_RenderCore!RenderingThreadMain() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\rendercore\private\renderingthread.cpp:325]
UE4Editor_RenderCore!FRenderingThread::Run() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\rendercore\private\renderingthread.cpp:459]
UE4Editor_Core!FRunnableThreadWin::Run() [d:\build++ue4+release-4.17+compile\sync\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:76]