Suddenly compiling any project with C++ in it gives me undeclared identifier errors [closed]

It all started with a blank function in C++ giving me this weird error saying there was an unidentified symbol. It was blank and I didn’t need it so I deleted that code eventually, no big deal. Then it started happening with everything new. After trying for over an hour I restarted my computer thinking it might be some weird VS glitch, but it still happened. Now it is even happening on old projects that had zero issues. It keeps giving me declared identifier errors. Here are the errors it gave me with a different file

Should I reinstall VS2013 and/or Unreal 4.9?

EDIT: I updated my VS2013 and tried to clean rebuild the files. Now it says (or maybe it did before and I somehow missed it) that it cannot open up the ToggleForBP.generated.h file. I check to make sure it wasn’t set on read only and it isn’t. I am very confused right now.

My .h
// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "GameFramework/Actor.h"
#include "ToggleForBP.generated.h"

class PLAYGROUND_API AToggleForBP : public AActor
	// Sets default values for this actor's properties

	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

	// Called every frame
	virtual void Tick(float DeltaSeconds) override;

	//Toggles between on and off
	void SwitchOnOff();

	bool UniqueValueBlah;


My .cpp

// Fill out your copyright notice in the Description page of Project Settings.

#include "Playground.h"
#include "ToggleForBP.h"

// Sets default values
 	// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;


void SwitchOnOff()

	UniqueValueBlah = true;

// Called when the game starts or when spawned
void AToggleForBP::BeginPlay()

// Called every frame
void AToggleForBP::Tick( float DeltaTime )
	Super::Tick( DeltaTime );


The errors I get from VS2013

Error	2	error : Failed to produce item: D:\Unreal Projects\Playground\Binaries\Win64\UE4Editor-Playground-3827.dll	D:\Unreal Projects\Playground\Intermediate\ProjectFiles\ERROR	Playground
Error	1	error C2065: 'UniqueValueBlah' : undeclared identifier	D:\Unreal Projects\Playground\Source\Playground\ToggleForBP.cpp	18	1	Playground
Error	3	error MSB3073: The command ""D:\Programs\Epic Games\Epic Games\4.9\Engine\Build\BatchFiles\Build.bat" PlaygroundEditor Win64 Development "D:\Unreal Projects\Playground\Playground.uproject" -rocket -waitmutex" exited with code -1.	C:\Program Files (x86)\MSBuild\Microsoft.Cpp\v4.0\V120\Microsoft.MakeFile.Targets	38	5	Playground
	4	IntelliSense: identifier "UniqueValueBlah" is undefined	d:\Unreal Projects\Playground\Source\Playground\ToggleForBP.cpp	18	2	Playground

I realized this might be a general C++ error instead of Unreal Engine based and sure enough it was. Turns out I needed to add AToggleForBP:: to my function because without it the compiler thought I was calling a global function!

didnt realize i forget the prefix until see your answer,i was so dumb,thanks for posting this.