[CRASH] Creating new font from struct editor makes crash of editor

When I creating new SlateFontInfo field in blueprint struct, I want to specify default value.
So I already have font named Roboto in my catalog, and I want to specify this font as default, but I don’t see anything in dropdown list.

Okay, I go create new font, by clicking “create new”, and I got new font dialog window. So I click New Item, and editor goes to assertions in C++ code and crashes after.

First assertion:

ensure(OwnerStruct == UserDefinedStruct.Get()); in void FDefaultValueDetails::OnFinishedChangingProperties(const FPropertyChangedEvent& PropertyChangedEvent) of UserDefinedStructureEditor.cpp

Second:

UE_LOG(LogCasts, Fatal, TEXT("Cast of %s to %s failed"), FromType, ToType); in void CastLogError(const TCHAR* FromType, const TCHAR* ToType) of Casts.cpp goes from const TArray& FStructureEditorUtils::GetVarDesc(const UUserDefinedStruct* Struct) (return CastChecked(Struct->EditorData)->VariablesDescriptions;)

UPD: I clicked at Engine content and found engine Roboto fonts. Then I clicked to one of them and got same crash.

This crash appears to have been resolved for 4.12. I can reproduce it in 4.11, but not in 4.12.

Thank you!