bt
#0  0x00007fffec931a27 in raise () from /lib64/libc.so.6
#1  0x00007fffec932dba in abort () from /lib64/libc.so.6
#2  0x00007fffec92a88d in ?? () from /lib64/libc.so.6
#3  0x00007fffec92a942 in __assert_fail () from /lib64/libc.so.6
#4  0x00007fffcfebf64a in ?? () from /usr/lib64/dri/i965_dri.so
#5  0x00007fffcfebfba3 in ?? () from /usr/lib64/dri/i965_dri.so
#6  0x00007fffcfeb8ef1 in ?? () from /usr/lib64/dri/i965_dri.so
#7  0x00007fffcfbbf02d in ?? () from /usr/lib64/dri/i965_dri.so
#8  0x00007fffcfbbf272 in ?? () from /usr/lib64/dri/i965_dri.so
#9  0x00007fffd2cf22cd in FOpenGLDynamicRHI::ReadSurfaceDataRaw (this=<optimized out>, ContextState=..., TextureRHI=<optimized out>, Rect=..., OutData=..., InFlags=...)
    at Engine/Source/Runtime/OpenGLDrv/Private/OpenGLRenderTarget.cpp:683
#10 0x00007fffd2cf287e in FOpenGLDynamicRHI::RHIReadSurfaceData (this=0x1c42000, TextureRHI=0x8241040, Rect=..., OutData=..., InFlags=...)
    at Engine/Source/Runtime/OpenGLDrv/Private/OpenGLRenderTarget.cpp:712
#11 0x00007ffff201842a in ReadSurfaceData_Internal (Texture=0x8241040, Rect=..., OutData=..., InFlags=...) at Runtime/RHI/Public/RHIMethods.h:1241
#12 0x00007ffff476c07d in ReadSurfaceData (this=<optimized out>, OutData=..., Texture=<optimized out>, Rect=..., InFlags=...)
    at Engine/Source/Runtime/RHI/Public/RHIMethods.h:1241
#13 FViewport::GetRawHitProxyData(FIntRect)::EURCMacro_ReadSurfaceCommand::DoTask(ENamedThreads::Type, TRefCountPtr<FGraphEvent> const&) (this=<optimized out>, 
    CurrentThread=ENamedThreads::StatsThread, MyCompletionGraphEvent=...)
    at Engine/Source/Runtime/Engine/Private/UnrealClient.cpp:1139
#14 0x00007ffff47c6d72 in TGraphTask<FViewport::GetRawHitProxyData(FIntRect)::EURCMacro_ReadSurfaceCommand>::ExecuteTask(TArray<FBaseGraphTask*, FDefaultAllocator>&, ENamedThreads::Type) (this=0x7fffc4042300, NewTasks=..., CurrentThread=6)
    at Engine/Source/Runtime/Core/Public/Async/TaskGraphInterfaces.h:667
#15 0x00007ffff715ddae in Execute (this=0x7fffc4042300, NewTasks=..., CurrentThread=6) at Runtime/Core/Public/Async/TaskGraphInterfaces.h:300
#16 FTaskThread::ProcessTasks (this=0x113fa08, QueueIndex=0, bAllowStall=true)
    at Engine/Source/Runtime/Core/Private/Async/TaskGraph.cpp:426
#17 0x00007ffff715b025 in ProcessTasksUntilQuit (this=0x113fa08, QueueIndex=<optimized out>)
    at Engine/Source/Runtime/Core/Private/Async/TaskGraph.cpp:269
#18 FTaskGraphImplementation::ProcessThreadUntilRequestReturn (this=<optimized out>, CurrentThread=<optimized out>)
    at Engine/Source/Runtime/Core/Private/Async/TaskGraph.cpp:939
#19 0x00007ffff225ff9f in RenderingThreadMain (TaskGraphBoundSyncEvent=<optimized out>)
    at Engine/Source/Runtime/RenderCore/Private/RenderingThread.cpp:281
#20 0x00007ffff227e3c0 in FRenderingThread::Run (this=<optimized out>)
    at Engine/Source/Runtime/RenderCore/Private/RenderingThread.cpp:404
#21 0x00007ffff710f85e in FRunnableThreadPThread::Run (this=0x8d2ffa0)
    at Engine/Source/Runtime/Core/Private/HAL/PThreadRunnableThread.cpp:22
#22 0x00007ffff7156fb2 in FRunnableThreadPThread::_ThreadProc (pThis=0x8d2ffa0) at Runtime/Core/Private/GenericPlatform/../HAL/PThreadRunnableThread.h:197
#23 0x00007ffff7bc72d4 in start_thread () from /lib64/libpthread.so.0
#24 0x00007fffec9e81fd in clone () from /lib64/libc.so.6