UE4 Crashes when landscape editor deletes material

The editor crashes when I try to delete part of my landscape. Here is the log error file

Log file open, 04/15/18 20:35:34
LogWindows: Failed to load ‘aqProf.dll’ (GetLastError=126)
LogWindows: File ‘aqProf.dll’ does not exist
LogWindows: Failed to load ‘VtuneApi.dll’ (GetLastError=126)
LogWindows: File ‘VtuneApi.dll’ does not exist
LogWindows: Failed to load ‘VtuneApi32e.dll’ (GetLastError=126)
LogWindows: File ‘VtuneApi32e.dll’ does not exist
LogInit: Display: Running engine for game: Sandbox
LogPlatformFile: Not using cached read wrapper
LogInit: Display: RandInit(-1007617422) SRandInit(-1007617422).
LogInit: Read version file with build ID ‘3944462’
LogInit: Overriding engine version to CL 3989454, compatible CL 3944462
LogInit: Registered custom module enumerator with build ID ‘3944462’
LogTaskGraph: Started task graph with 5 named threads and 23 total threads with 3 sets of task threads.
LogStats: Stats thread started at 0.297174
LogD3D11RHI: Aftermath initialized
LogICUInternationalization: Display: ICU TimeZone Detection - Raw Offset: -6:00, Platform Override: ‘’
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-Paper2D.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-Paper2DEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-PaperSpriteSheetImporter.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-PaperTiledImporter.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/2D/Paper2D/Binaries/Win64/UE4Editor-SmartSnapping.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Blendables/LightPropagationVolume/Binaries/Win64/UE4Editor-LightPropagationVolumeRuntime.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Blendables/LightPropagationVolume/Binaries/Win64/UE4Editor-LightPropagationVolumeEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/CLionSourceCodeAccess/Binaries/Win64/UE4Editor-CLionSourceCodeAccess.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/GitSourceControl/Binaries/Win64/UE4Editor-GitSourceControl.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/PerforceSourceControl/Binaries/Win64/UE4Editor-PerforceSourceControl.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/SubversionSourceControl/Binaries/Win64/UE4Editor-SubversionSourceControl.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/UObjectPlugin/Binaries/Win64/UE4Editor-UObjectPlugin.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/VisualStudioCodeSourceCodeAccess/Binaries/Win64/UE4Editor-VisualStudioCodeSourceCodeAccess.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Developer/VisualStudioSourceCodeAccess/Binaries/Win64/UE4Editor-VisualStudioSourceCodeAccess.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/AssetManagerEditor/Binaries/Win64/UE4Editor-AssetManagerEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/CryptoKeys/Binaries/Win64/UE4Editor-CryptoKeys.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/CryptoKeys/Binaries/Win64/UE4Editor-CryptoKeysOpenSSL.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/DataValidation/Binaries/Win64/UE4Editor-DataValidation.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/FacialAnimation/Binaries/Win64/UE4Editor-FacialAnimation.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/FacialAnimation/Binaries/Win64/UE4Editor-FacialAnimationEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/GameplayTagsEditor/Binaries/Win64/UE4Editor-GameplayTagsEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/MobileLauncherProfileWizard/Binaries/Win64/UE4Editor-MobileLauncherProfileWizard.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/PluginBrowser/Binaries/Win64/UE4Editor-PluginBrowser.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Editor/SpeedTreeImporter/Binaries/Win64/UE4Editor-SpeedTreeImporter.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Enterprise/DatasmithContent/Binaries/Win64/UE4Editor-DatasmithContent.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Experimental/AlembicImporter/Binaries/Win64/UE4Editor-AlembicImporter.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Experimental/AlembicImporter/Binaries/Win64/UE4Editor-AlembicLibrary.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Experimental/CharacterAI/Binaries/Win64/UE4Editor-CharacterAI.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Experimental/HTML5Networking/Binaries/Win64/UE4Editor-HTML5Networking.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/AndroidMedia/Binaries/Win64/UE4Editor-AndroidMediaEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/AndroidMedia/Binaries/Win64/UE4Editor-AndroidMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/AvfMedia/Binaries/Win64/UE4Editor-AvfMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMedia.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-ImgMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/ImgMedia/Binaries/Win64/UE4Editor-OpenExrWrapper.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/LinearTimecode/Binaries/Win64/UE4Editor-LinearTimecode.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/MediaCompositing/Binaries/Win64/UE4Editor-MediaCompositing.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/MediaCompositing/Binaries/Win64/UE4Editor-MediaCompositingEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/MediaPlayerEditor/Binaries/Win64/UE4Editor-MediaPlayerEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMedia.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Media/WmfMedia/Binaries/Win64/UE4Editor-WmfMediaFactory.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Messaging/TcpMessaging/Binaries/Win64/UE4Editor-TcpMessaging.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Messaging/UdpMessaging/Binaries/Win64/UE4Editor-UdpMessaging.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/MovieScene/ActorSequence/Binaries/Win64/UE4Editor-ActorSequence.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/MovieScene/LevelSequenceEditor/Binaries/Win64/UE4Editor-LevelSequenceEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/MovieScene/MatineeToLevelSequence/Binaries/Win64/UE4Editor-MatineeToLevelSequence.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/NetcodeUnitTest/NetcodeUnitTest/Binaries/Win64/UE4Editor-NetcodeUnitTest.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/NetcodeUnitTest/NUTUnrealEngine4/Binaries/Win64/UE4Editor-NUTUnrealEngine4.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Online/OnlineSubsystem/Binaries/Win64/UE4Editor-OnlineSubsystem.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/AndroidPermission/Binaries/Win64/UE4Editor-AndroidPermission.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Online/OnlineSubsystemNull/Binaries/Win64/UE4Editor-OnlineSubsystemNull.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Online/OnlineSubsystemUtils/Binaries/Win64/UE4Editor-OnlineSubsystemUtils.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Online/OnlineSubsystemUtils/Binaries/Win64/UE4Editor-OnlineBlueprintSupport.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/AndroidDeviceProfileSelector/Binaries/Win64/UE4Editor-AndroidDeviceProfileSelector.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/AppleARKit/Binaries/Win64/UE4Editor-AppleARKit.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ProceduralMeshComponent/Binaries/Win64/UE4Editor-ProceduralMeshComponent.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ProceduralMeshComponent/Binaries/Win64/UE4Editor-ProceduralMeshComponentEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Animation/LiveLink/Binaries/Win64/UE4Editor-LiveLink.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Animation/LiveLink/Binaries/Win64/UE4Editor-LiveLinkEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ArchVisCharacter/Binaries/Win64/UE4Editor-ArchVisCharacter.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/AudioCapture/Binaries/Win64/UE4Editor-AudioCapture.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/AudioCapture/Binaries/Win64/UE4Editor-AudioCaptureEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/CableComponent/Binaries/Win64/UE4Editor-CableComponent.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/CustomMeshComponent/Binaries/Win64/UE4Editor-CustomMeshComponent.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ExampleDeviceProfileSelector/Binaries/Win64/UE4Editor-ExampleDeviceProfileSelector.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ImmediatePhysics/Binaries/Win64/UE4Editor-ImmediatePhysics.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/ImmediatePhysics/Binaries/Win64/UE4Editor-ImmediatePhysicsEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/LocationServicesBPLibrary/Binaries/Win64/UE4Editor-LocationServicesBPLibrary.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/MobilePatchingUtils/Binaries/Win64/UE4Editor-MobilePatchingUtils.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusHMD.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusInput.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/Oculus/OculusVR/Binaries/Win64/UE4Editor-OculusEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/PhysXVehicles/Binaries/Win64/UE4Editor-PhysXVehicles.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/PhysXVehicles/Binaries/Win64/UE4Editor-PhysXVehiclesEditor.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/RuntimePhysXCooking/Binaries/Win64/UE4Editor-RuntimePhysXCooking.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/Steam/SteamVR/Binaries/Win64/UE4Editor-SteamVR.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/Steam/SteamVR/Binaries/Win64/UE4Editor-SteamVRController.dll (API version 3944462).
LogModuleManager: Display: Found up-to-date module file …/…/…/Engine/Plugins/Runtime/WindowsMoviePlayer/Binaries/Win64/UE4Editor-WindowsMoviePlayer.dll (API version 3944462).
LogPluginManager: Mounting plugin Paper2D
LogPluginManager: Mounting plugin LiveLink