Crash converting code project 4.7 to 4.8 ; Array index out of Bounds

Some users are experiencing a crash when converting their project from 4.7 to 4.8. From user reports it appears to be affecting those who have added code to their projects and created blueprints based on their code classes. I've not been able to reproduce locally as of yet.

Error message:

Assertion failed: (Index >= 0) & (Index < ArrayNum) [Link Removed] [Line: 678] Array index out of bounds: 11 from an array of size 11

Answerhub Links:
https://answers.unrealengine.com/questions/241435/crash-when-open-a-48-project.html
https://answers.unrealengine.com/questions/240996/serialize-causes-crash.html
Crash reporter:
[Link Removed]
Bugg:
[Link Removed]

Haven't been able to reproduce locally as of yet.

UE4Editor_BlueprintGraph!UK2Node::ExpandSplitPin() k2node.cpp:687
UE4Editor_KismetCompiler!FKismetCompilerContext::ExpandTunnelsAndMacros() kismetcompiler.cpp:2902
UE4Editor_KismetCompiler!FKismetCompilerContext::ExpansionStep() kismetcompiler.cpp:2535
UE4Editor_KismetCompiler!FKismetCompilerContext::ProcessOneFunctionGraph() kismetcompiler.cpp:3043
UE4Editor_KismetCompiler!FKismetCompilerContext::CreateFunctionList() kismetcompiler.cpp:3132
UE4Editor_KismetCompiler!FKismetCompilerContext::Compile() kismetcompiler.cpp:3371
UE4Editor_KismetCompiler!FKismet2CompilerModule::CompileBlueprintInner() kismetcompilermodule.cpp:99
UE4Editor_KismetCompiler!FKismet2CompilerModule::CompileBlueprint() kismetcompilermodule.cpp:155
UE4Editor_UnrealEd!FKismetEditorUtilities::GenerateBlueprintSkeleton() kismet2.cpp:893
UE4Editor_UnrealEd!FBlueprintEditorUtils::RegenerateBlueprintClass() blueprinteditorutils.cpp:1412
UE4Editor_CoreUObject!FLinkerLoad::RegenerateBlueprintClass() blueprintsupport.cpp:332
UE4Editor_CoreUObject!FLinkerLoad::FinalizeBlueprint() blueprintsupport.cpp:1140
UE4Editor_CoreUObject!FLinkerLoad::Preload() linkerload.cpp:3098
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() linkerload.cpp:3698
UE4Editor_CoreUObject!FLinkerLoad::IndexToObject() linkerload.cpp:3882
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() linkerload.cpp:3413
UE4Editor_CoreUObject!FLinkerLoad::IndexToObject() linkerload.cpp:3882
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() linkerload.cpp:3413
UE4Editor_CoreUObject!FLinkerLoad::CreateExportAndPreload() linkerload.cpp:2581
UE4Editor_CoreUObject!FLinkerLoad::LoadAllObjects() linkerload.cpp:2689
UE4Editor_CoreUObject!LoadPackageInternal() uobjectglobals.cpp:997
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2274
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2322
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::Verify() linkerload.cpp:1827
UE4Editor_CoreUObject!FLinkerLoad::FinalizeCreation() linkerload.cpp:1737
UE4Editor_CoreUObject!FLinkerLoad::Tick() linkerload.cpp:627
UE4Editor_CoreUObject!FLinkerLoad::CreateLinker() linkerload.cpp:371
UE4Editor_CoreUObject!GetPackageLinker() linker.cpp:558
UE4Editor_CoreUObject!LoadPackageInternal() uobjectglobals.cpp:931
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2274
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2322
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::Verify() linkerload.cpp:1827
UE4Editor_CoreUObject!FLinkerLoad::FinalizeCreation() linkerload.cpp:1737
UE4Editor_CoreUObject!FLinkerLoad::Tick() linkerload.cpp:627
UE4Editor_CoreUObject!FLinkerLoad::CreateLinker() linkerload.cpp:371
UE4Editor_CoreUObject!GetPackageLinker() linker.cpp:558
UE4Editor_CoreUObject!LoadPackageInternal() uobjectglobals.cpp:931
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2274
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2322
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::Verify() linkerload.cpp:1827
UE4Editor_CoreUObject!FLinkerLoad::FinalizeCreation() linkerload.cpp:1737
UE4Editor_CoreUObject!FLinkerLoad::Tick() linkerload.cpp:627
UE4Editor_CoreUObject!FLinkerLoad::CreateLinker() linkerload.cpp:371
UE4Editor_CoreUObject!GetPackageLinker() linker.cpp:558
UE4Editor_CoreUObject!LoadPackageInternal() uobjectglobals.cpp:931
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2274
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::VerifyImportInner() linkerload.cpp:2322
UE4Editor_CoreUObject!FLinkerLoad::VerifyImport() linkerload.cpp:2037
UE4Editor_CoreUObject!FLinkerLoad::CreateImport() linkerload.cpp:3832
UE4Editor_CoreUObject!FLinkerLoad::ResolveDependencyPlaceholder() blueprintsupport.cpp:943
UE4Editor_CoreUObject!FLinkerLoad::ResolveDeferredDependencies() blueprintsupport.cpp:821
UE4Editor_CoreUObject!FLinkerLoad::FinalizeBlueprint() blueprintsupport.cpp:1058
UE4Editor_CoreUObject!FLinkerLoad::Preload() linkerload.cpp:3098
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() linkerload.cpp:3698
UE4Editor_CoreUObject!FLinkerLoad::IndexToObject() linkerload.cpp:3882
UE4Editor_CoreUObject!FLinkerLoad::CreateExport() linkerload.cpp:3413
UE4Editor_CoreUObject!FLinkerLoad::IndexToObject() linkerload.cpp:3882