Projects crashing on launch after converting from 4.7.3 to 4.7.4

A couple users have reported a crash when opening their 4.7.3 project in 4.7.4.

From MikeB:
https://answers.unrealengine.com/questions/205043/473-to-474-project-crash-on-startup.html

The guy is hitting a bunch of ensures (that are confusing), and then crashes on load in DestroyPersistentUberGraphFrame(). It is probably worth trying to load up his BP/project. Don't know if the one asset will be enough (doubt it).

https://answers.unrealengine.com/questions/205110/my-project-after-updating-474-doomed.html

Possibly related to the above issue though? This one's an error with UK2Node_SetVariableOnPersistentFrame not being able to find the corresponding local variable on compile.

Crash info from the first user project:
Crash Reporter:
[Link Removed]

Call Stack:
UE4Editor_Core! scalable_msize() frontend.cpp:2615
UE4Editor_Core! FMallocTBB::Free() malloctbb.cpp:109
UE4Editor_CoreUObject! TProperty<FString,UProperty>::DestroyValueInternal() unrealtype.h:996
UE4Editor_Engine! UBlueprintGeneratedClass::DestroyPersistentUberGraphFrame() blueprintgeneratedclass.cpp:608
UE4Editor_CoreUObject! UObjectBase::SetClass() uobjectbase.cpp:263
UE4Editor_UnrealEd! FBlueprintCompileReinstancer::FBlueprintCompileReinstancer() kismetreinstanceutilities.cpp:165
UE4Editor_UnrealEd! FKismetEditorUtilities::RecompileBlueprintBytecode() kismet2.cpp:906
UE4Editor_Engine! UBlueprintGeneratedClass::ConditionalRecompileClass() blueprintgeneratedclass.cpp:247
UE4Editor_CoreUObject! FScopedClassDependencyGather::~FScopedClassDependencyGather() blueprintsupport.cpp:133
UE4Editor_CoreUObject! ULinkerLoad::CreateExport() linkerload.cpp:3617
UE4Editor_CoreUObject! ULinkerLoad::IndexToObject() linkerload.cpp:3809
UE4Editor_CoreUObject! ULinkerLoad::CreateExport() linkerload.cpp:3334
UE4Editor_CoreUObject! ULinkerLoad::IndexToObject() linkerload.cpp:3809
UE4Editor_CoreUObject! ULinkerLoad::CreateExport() linkerload.cpp:3334
UE4Editor_CoreUObject! ULinkerLoad::CreateExportAndPreload() linkerload.cpp:2520
UE4Editor_CoreUObject! ULinkerLoad::LoadAllObjects() linkerload.cpp:2628
UE4Editor_CoreUObject! LoadPackageInternal() uobjectglobals.cpp:894
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2213
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::Verify() linkerload.cpp:1768
UE4Editor_CoreUObject! ULinkerLoad::FinalizeCreation() linkerload.cpp:1674
UE4Editor_CoreUObject! ULinkerLoad::Tick() linkerload.cpp:634
UE4Editor_CoreUObject! ULinkerLoad::CreateLinker() linkerload.cpp:382
UE4Editor_CoreUObject! GetPackageLinker() linker.cpp:668
UE4Editor_CoreUObject! LoadPackageInternal() uobjectglobals.cpp:835
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2213
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::Verify() linkerload.cpp:1768
UE4Editor_CoreUObject! ULinkerLoad::FinalizeCreation() linkerload.cpp:1674
UE4Editor_CoreUObject! ULinkerLoad::Tick() linkerload.cpp:634
UE4Editor_CoreUObject! ULinkerLoad::CreateLinker() linkerload.cpp:382
UE4Editor_CoreUObject! GetPackageLinker() linker.cpp:668
UE4Editor_CoreUObject! LoadPackageInternal() uobjectglobals.cpp:835
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2213
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::Verify() linkerload.cpp:1768
UE4Editor_CoreUObject! ULinkerLoad::FinalizeCreation() linkerload.cpp:1674
UE4Editor_CoreUObject! ULinkerLoad::Tick() linkerload.cpp:634
UE4Editor_CoreUObject! ULinkerLoad::CreateLinker() linkerload.cpp:382
UE4Editor_CoreUObject! GetPackageLinker() linker.cpp:668
UE4Editor_CoreUObject! LoadPackageInternal() uobjectglobals.cpp:835
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2213
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::Verify() linkerload.cpp:1768
UE4Editor_CoreUObject! ULinkerLoad::FinalizeCreation() linkerload.cpp:1674
UE4Editor_CoreUObject! ULinkerLoad::Tick() linkerload.cpp:634
UE4Editor_CoreUObject! ULinkerLoad::CreateLinker() linkerload.cpp:382
UE4Editor_CoreUObject! GetPackageLinker() linker.cpp:668
UE4Editor_CoreUObject! LoadPackageInternal() uobjectglobals.cpp:835
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2213
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::VerifyImportInner() linkerload.cpp:2261
UE4Editor_CoreUObject! ULinkerLoad::VerifyImport() linkerload.cpp:1978
UE4Editor_CoreUObject! ULinkerLoad::Verify() linkerload.cpp:1768

Not reproduced internally.

1. Open project in 4.7.4 (see comments)

Result:
Crash