Unreal Engine 4.20 crashes when I try to play?

Question

I'm making a Simple escape the room game using unreal 4.20 and C++ on my Windows 10 Machine. The code builds/complies just fine but when I hit play the Engines crashes. I've tried restarting my computer, deleting all files files/directories except for config, content, source folders, and the .uproject file. I tried deleting the engine, but it won't let me due to administrator permissions. I'm currently on the "Open door" class

Here is my OpenDoor.h file:

 #pragma once

 #include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "Engine/TriggerVolume.h"
#include "OpenDoor.generated.h"


 UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
 class BUILDINGESCAPE_API UOpenDoor : public UActorComponent
 {
    GENERATED_BODY()

  public:   
  // Sets default values for this component's properties
   UOpenDoor();

 protected:
  // Called when the game starts
  virtual void BeginPlay() override;
 private:
  void OpenDoor();

  // Called every frame
  virtual void TickComponent(float DeltaTime, ELevelTick TickType, 
   FActorComponentTickFunction* ThisTickFunction) override;
 public:
   UPROPERTY(VisibleAnywhere)
     float OpenAngle = 90.0f; 
   UPROPERTY(EditAnywhere)
     ATriggerVolume* PressurePlate;

   UPROPERTY(EditAnywhere)
     AActor* ActorThatOpens; // Remember pawn inherits from actor


   };

Here is my OpenDoor.cpp file:

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

#include "OpenDoor.h"


// Sets default values for this component's properties
UOpenDoor::UOpenDoor()
{
// Set this component to be initialized when the game starts, and to be 
 ticked every frame.  You can turn these features
   // off to improve performance if you don't need them.
  PrimaryComponentTick.bCanEverTick = true;

  // ...
 }


// Called when the game starts
void UOpenDoor::BeginPlay()
{
 Super::BeginPlay();


 // ...

}
void UOpenDoor::OpenDoor()
{
  // Find the owning Actor
  AActor* Owner = GetOwner();
 }

// Called every frame
void UOpenDoor::TickComponent(float DeltaTime, ELevelTick TickType, 
FActorComponentTickFunction* ThisTickFunction)
{
  Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

   // Poll the Trigger Volume
   // If the ActorThatOpens is in the volume
   if (PressurePlate->IsOverlappingActor(ActorThatOpens))
    {
     OpenDoor();
    }
} 

I'm new to Unreal and struggle with C++ as a language in General, so I wonder if its an issue with my code. Any help would be greatly appreciated. Thanks!

Answer 1

You have to check the null pointers of the

PressurePlate

and the

ActorThatOpens

It's also a good practice to secure all pointers before using them so you don't get a crash for deferencing null pointers. Even so, your code should work, probably you are forgetting to set the reference on the editor.

I fixed that for you:

void UOpenDoor::OpenDoor()
{
  // Find the owning Actor
  if(!GetOwner()) return;
  AActor* Owner = GetOwner();
 }

// Called every frame
void UOpenDoor::TickComponent(float DeltaTime, ELevelTick TickType, 
FActorComponentTickFunction* ThisTickFunction)
{
  Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

   // Poll the Trigger Volume
   // If the ActorThatOpens is in the volume
   if (PressurePlate == nullptr) //Checking for the PressurePlate
   {
      UE_LOG(LogTemp, Warning, TEXT("Missing PressurePlate");
      return;
   }
   if(ActorThatOpens == nullptr) // Checking for the Door
   {
   UE_LOG(LogTemp, Warning, TEXT("Missing ActorThatOpens");
   return;
   }
   if (PressurePlate->IsOverlappingActor(ActorThatOpens))
    {
     OpenDoor();
    }
}