Unreal Engine Issues and Bug Tracker (UE-48800)

Description

The editor crashes with an Access Violation if a node that was copied and pasted from the Blueprint Diff tools is removed via an undo.

Regression?: No
This issue also occurred in 4.16

Branches tested:
4.16.3-3561208+++UE4+Release-4.16
4.17.1-3586342+++UE4+Release-4.17
4.18.0-3582225+++UE4+Main

Steps to Reproduce

Open a project that is part of a Perforce depot
Create a new blueprint, save it, and add it to Perforce
Add a new node to the blueprint's Event Graph (IsValid macro works)
In the Blueprint Editor, click File > Diff > Depot
Open the "EventGraph" dropdown, click on the "Added node" event and then select the IsValid node in the preview graph and copy it (Ctrl+C)
Back in the actual Event Graph, paste the node (Ctrl+V)
Undo the action of pasting the node
Result: The editor crashes with an access violation
Expected: The action is undone successfully and the node is removed from the EventGraph

Callstack

Fatal error!

Unhandled Exception: EXCEPTION_ACCESS_VIOLATION reading address 0xffffffff

UE4Editor-CoreUObject.dll!UObjectBaseUtility::IsA() [d:\matthew.clark_main_stream\engine\source\runtime\coreuobject\private\uobject\uobjectbaseutility.cpp:278]
UE4Editor-Engine.dll!UEdGraphNode::GetGraph() [d:\matthew.clark_main_stream\engine\source\runtime\engine\private\edgraph\edgraphnode.cpp:284]
UE4Editor-Engine.dll!UEdGraphPin::GetSchema() [d:\matthew.clark_main_stream\engine\source\runtime\engine\private\edgraph\edgraphpin.cpp:535]
UE4Editor-GraphEditor.dll!SGraphPin::GetPinIcon() [d:\matthew.clark_main_stream\engine\source\editor\grapheditor\private\sgraphpin.cpp:875]
UE4Editor-Slate.dll!TAttribute<FSlateBrush const * __ptr64>::Get() [d:\matthew.clark_main_stream\engine\source\runtime\core\public\misc\attribute.h:137]
UE4Editor-Slate.dll!SImage::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\images\simage.cpp:15]
UE4Editor-KismetWidgets.dll!SDoubleImage::OnPaint() [d:\matthew.clark_main_stream\engine\source\editor\kismetwidgets\private\spintypeselector.cpp:47]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-Slate.dll!SBorder::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:85]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-Slate.dll!SBorder::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:85]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SOverlay::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:97]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-GraphEditor.dll!SNodePanel::SNode::OnPaint() [d:\matthew.clark_main_stream\engine\source\editor\grapheditor\public\snodepanel.h:420]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-GraphEditor.dll!SGraphPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\editor\grapheditor\private\sgraphpanel.cpp:256]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SOverlay::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:97]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-Slate.dll!SBox::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sbox.cpp:245]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-Slate.dll!SBox::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sbox.cpp:245]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-Slate.dll!SSplitter::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:167]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-Slate.dll!SBorder::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:85]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SOverlay::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:97]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-Slate.dll!SSplitter::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:167]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SOverlay::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:97]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-Slate.dll!SSplitter::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:167]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-Slate.dll!SBorder::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:85]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-Slate.dll!SBox::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sbox.cpp:245]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SOverlay::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\soverlay.cpp:97]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-Slate.dll!SSplitter::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\ssplitter.cpp:167]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-Slate.dll!SBorder::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slate\private\widgets\layout\sborder.cpp:85]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SCompoundWidget::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\scompoundwidget.cpp:35]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]
UE4Editor-SlateCore.dll!SPanel::PaintArrangedChildren() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:31]
UE4Editor-SlateCore.dll!SPanel::OnPaint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\spanel.cpp:12]
UE4Editor-SlateCore.dll!SWidget::Paint() [d:\matthew.clark_main_stream\engine\source\runtime\slatecore\private\widgets\swidget.cpp:899]

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Fixed

Component	UE - Gameplay - Blueprint Editor
Affects Versions	4.16, 4.17, 4.18
Target Fix	4.18

Fix Commit	3613841
Main Commit	3628687
Release Commit	3643070

Created	Aug 24, 2017
Resolved	Aug 28, 2017
Updated	Aug 9, 2018

UE-48800

Undoing the pasting of a copied node from the Blueprint Diff tools causes an access violation crash

Undoing the pasting of a copied node from the Blueprint Diff tools causes an access violation crash

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