This is an infrequent BSP crash occurring for users in 4.17
User Descriptions
Source Context
1182 // Get the brush poly. 1183 FPoly DestEdPoly = CurrentPoly; 1184 check(CurrentPoly.iLink<Brush->Polys->Element.Num()); 1185 1186 // Set its backward brush link. 1187 ***** DestEdPoly.Actor = Actor; 1188 DestEdPoly.iBrushPoly = i; 1189 1190 // Update its flags. 1191 DestEdPoly.PolyFlags = (DestEdPoly.PolyFlags | PolyFlags) & ~NotPolyFlags;
repro steps currently unknown
Assertion failed: CurrentPoly.iLink<Brush->Polys->Element.Num() [File:D:\Build\++UE4+Release-4.17+Compile\Sync\Engine\Source\Editor\UnrealEd\Private\EditorBsp.cpp] [Line: 1185] UE4Editor_UnrealEd!UEditorEngine::bspBrushCSG() [editorbsp.cpp:1188] UE4Editor_UnrealEd!UEditorEngine::RebuildModelFromBrushes() [editorserver.cpp:1789] UE4Editor_UnrealEd!UEditorEngine::RebuildLevel() [editorserver.cpp:1680] UE4Editor_UnrealEd!UEditorEngine::RebuildAlteredBSP() [editorserver.cpp:1873] UE4Editor_Engine!ABrush::PostEditChangeProperty() [brush.cpp:107] UE4Editor_CoreUObject!UObject::PostEditChange() [obj.cpp:333] UE4Editor_UnrealEd!UUnrealEdEngine::edactAlignVertices() [editoractor.cpp:2484] UE4Editor_UnrealEd!UUnrealEdEngine::Exec_Actor() [unrealedsrv.cpp:2745] UE4Editor_UnrealEd!UUnrealEdEngine::Exec() [unrealedsrv.cpp:729] UE4Editor_DetailCustomizations!`FBrushDetails::CustomizeDetails'::`2'::Local::ExecuteExecCommand() [brushdetails.cpp:103] UE4Editor_DetailCustomizations!UE4Tuple_Private::TTupleImpl<TIntegerSequence<unsigned int,0>,FString>::ApplyAfter<FReply() [tuple.h:422] UE4Editor_DetailCustomizations!TBaseStaticDelegateInstance<FReply __cdecl() [delegateinstancesimpl.h:958] UE4Editor_Slate!TBaseDelegate<FReply>::Execute() [delegatesignatureimpl.inl:537] UE4Editor_Slate!SButton::OnMouseButtonUp() [sbutton.cpp:282] UE4Editor_Slate!<lambda_1002768c627006711ef2f351a87ec0e7>::operator() [slateapplication.cpp:5199] UE4Editor_Slate!FEventRouter::Route<FReply,FEventRouter::FToLeafmostPolicy,FPointerEvent,<lambda_1002768c627006711ef2f351a87ec0e7> >() [slateapplication.cpp:232] UE4Editor_Slate!FSlateApplication::RoutePointerUpEvent() [slateapplication.cpp:5188] UE4Editor_Slate!FSlateApplication::ProcessMouseButtonUpEvent() [slateapplication.cpp:5690] UE4Editor_Slate!FSlateApplication::OnMouseUp() [slateapplication.cpp:5670] UE4Editor_Core!FWindowsApplication::ProcessDeferredMessage() [windowsapplication.cpp:1718] UE4Editor_Core!FWindowsApplication::DeferMessage() [windowsapplication.cpp:2161] UE4Editor_Core!FWindowsApplication::ProcessMessage() [windowsapplication.cpp:881] UE4Editor_Core!FWindowsApplication::AppWndProc() [windowsapplication.cpp:721] user32!UserCallWinProcCheckWow() user32!DispatchMessageWorker() UE4Editor_Core!FWindowsPlatformMisc::PumpMessages() [windowsplatformmisc.cpp:1009] UE4Editor!FEngineLoop::Tick() [launchengineloop.cpp:3151] UE4Editor!GuardedMain() [launch.cpp:166] UE4Editor!GuardedMainWrapper() [launchwindows.cpp:134] UE4Editor!WinMain() [launchwindows.cpp:210] UE4Editor!__scrt_common_main_seh() [exe_common.inl:253] kernel32!BaseThreadInitThunk() ntdll!RtlUserThreadStart()
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-49454 in the post.