Strangely enough this only happens in a particular level in our project after upgrading from 4.13 Multi-res branch to 4.15 Vanilla branch.
**The full error is:**
Assertion Failed: BoundState.Texture == nullptr || BoundState.Texture == Texture2D [File:C:\Engine\Source\Runtime\Engine\Private\Streaming\TextureStreamingBuild.cpp] [Line: 371]
**Here is the crash log:**
[2017.02.20-17.51.04:389][264]LogWindows:Error: === Critical error: ===
[2017.02.20-17.51.04:389][264]LogWindows:Error:
[2017.02.20-17.51.04:389][264]LogWindows:Error: Assertion failed: BoundState.Texture == nullptr || BoundState.Texture == Texture2D [File:C:\Users\unc0nnected\Perforce\YVR\4.15\Engine\Source\Runtime\Engine\Private\Streaming\TextureStreamingBuild.cpp] [Line: 371]
[2017.02.20-17.51.04:389][264]LogWindows:Error:
[2017.02.20-17.51.04:389][264]LogWindows:Error:
[2017.02.20-17.51.04:389][264]LogWindows:Error:
[2017.02.20-17.51.04:389][264]LogWindows:Error: KERNELBASE.dll!0x00000000EB3B7788
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Core.dll!FOutputDeviceWindowsError::Serialize() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\core\private\windows\windowsplatformoutputdevices.cpp:120]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Core.dll!FOutputDevice::Logf__VA() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\core\private\misc\outputdevice.cpp:70]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Core.dll!FDebug::AssertFailed() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\core\private\misc\assertionmacros.cpp:349]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingTextureLevelContext::GetBuildDataIndexRef() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\texturestreamingbuild.cpp:373]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingTextureLevelContext::ProcessMaterial() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\texturestreamingbuild.cpp:396]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!UMeshComponent::GetStreamingTextureInfoInner() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\components\meshcomponent.cpp:368]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!UStaticMeshComponent::GetStreamingTextureInfo() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\components\staticmeshcomponent.cpp:837]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!UPrimitiveComponent::GetStreamingTextureInfoWithNULLRemoval() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\components\primitivecomponent.cpp:292]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!FTextureInstanceState::AddComponent() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\textureinstancemanager.cpp:476]
[2017.02.20-17.51.04:389][264]LogWindows:Error: UE4Editor-Engine.dll!FLevelTextureManager::IncrementalBuild() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\textureinstancemanager.cpp:1459]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-Engine.dll!FLevelTextureManager::IncrementalUpdate() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\textureinstancemanager.cpp:1548]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingManagerTexture::IncrementalUpdate() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\streamingmanagertexture.cpp:360]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingManagerTexture::UpdateResourceStreaming() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\streaming\streamingmanagertexture.cpp:1170]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingManagerCollection::UpdateResourceStreaming() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\contentstreaming.cpp:709]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-Engine.dll!FStreamingManagerCollection::Tick() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\engine\private\contentstreaming.cpp:680]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-UnrealEd.dll!UEditorEngine::Tick() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\editor\unrealed\private\editorengine.cpp:1833]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor-UnrealEd.dll!UUnrealEdEngine::Tick() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\editor\unrealed\private\unrealedengine.cpp:391]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor.exe!FEngineLoop::Tick() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\launch\private\launchengineloop.cpp:3025]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor.exe!GuardedMain() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\launch\private\launch.cpp:166]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor.exe!GuardedMainWrapper() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\launch\private\windows\launchwindows.cpp:134]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor.exe!WinMain() [c:\users\unc0nnected\perforce\yvr\4.15\engine\source\runtime\launch\private\windows\launchwindows.cpp:210]
[2017.02.20-17.51.04:390][264]LogWindows:Error: UE4Editor.exe!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:253]
[2017.02.20-17.51.04:390][264]LogWindows:Error: KERNEL32.DLL!0x00000000EBCB8364
[2017.02.20-17.51.04:390][264]LogWindows:Error: ntdll.dll!0x00000000EE4870D1
[2017.02.20-17.51.04:390][264]LogWindows:Error: ntdll.dll!0x00000000EE4870D1
[2017.02.20-17.51.04:390][264]LogWindows:Error:
[2017.02.20-17.51.04:413][264]LogExit: Executing StaticShutdownAfterError
[2017.02.20-17.51.04:423][264]LogWindows: FPlatformMisc::RequestExit(1)
[2017.02.20-17.51.04:423][264]Log file closed, 02/20/17 12:51:04