Conversion of custom save files to UE 5.1

I am trying to convert a project I have from UE 4.23 to UE 5.1 and most stuff seems to be working correctly, however I had some functions in C++ used to save/load level file data from a basic level editor I made, and in UE 5.1 I cannot import and use those files because I saved them with a ‘.lvl’ extension and it always says it is unrecognized. Any ideas how to convert these data files into a useable format in UE 5.1 so I don’t lose them?

This is the code I was using to save them:

#define LEVEL_EXT ".lvl"
#define LEVEL_DIR "LevelFiles"

void ULevelDatav2::SaveGame(TArray<ABlock*> Actors, FString levelID) {
	TArray<FActorSaveData> SavedActors;
	for (auto Actor : Actors) {
		FActorSaveData ActorRecord;
		ActorRecord.ActorName = FName(*Actor->GetName());
		ActorRecord.ActorClass = Actor->GetClass()->GetPathName();
		ActorRecord.ActorTransform = Actor->GetTransform();

		FMemoryWriter MemoryWriter(ActorRecord.ActorData, true);
		FSaveGameArchive Ar(MemoryWriter);
		Actor->Serialize(Ar);

		SavedActors.Add(ActorRecord);
		//ISaveableActorInterface::Execute_ActorSaveDataSaved(Actor);
	}

	FSaveGameData SaveGameData;

	SaveGameData.GameID = *FString(levelID);
	SaveGameData.Timestamp = FDateTime::Now();
	SaveGameData.SavedActors = SavedActors;

	FBufferArchive BinaryData;

	BinaryData << SaveGameData;

	FString filename = FPaths::Combine(GetLevelSaveLocation(), levelID + LEVEL_EXT);
	if (FFileHelper::SaveArrayToFile(BinaryData, filename.GetCharArray().GetData()))
	{
		UE_LOG(LogTemp, Warning, TEXT("Save Success! %s"), *FString(filename));
	}
	else
	{
		UE_LOG(LogTemp, Warning, TEXT("Save Failed!"));
	}

	BinaryData.FlushCache();
	BinaryData.Empty();
}