FDataTableRowHandle using meta = (RequiredAssetDataTags = "RowStructure=S_StructName")?

In UE 5.2 this no longer works for UDataTable, in order to make it work you need to use this:

UPROPERTY(Meta=(RequiredAssetDataTags = "RowStructure=/Script/Aura.UIWidgetRow"))
TObjectPtr<UDataTable> MessageWidgetDataTable;

You can find the exact name here (picture below), it’s usually ModuleName.StructName (without the initial F)