Unity3D scene not working properly and lagging after reloading - unity3d

Question

I have looked all over internet, but I cannot find a solution to my problem. I am trying to create a game and it has 3 scenes: the Game Start, Main and Game over.
The problem is that when trying to load the main level from other scenes it does not do what it has to do (e.g. jump) and the scene itself is lagging. When I try to load only the Main Scene it works ok, but after the character dies and the scene is reloaded, it starts to lag again and I cannot jump or do anything it is supposed to do.
Any ideas on what the problem might be?
using UnityEngine;
using System;
public class Player : MonoBehaviour
{
// The force which is added when the player jumps
// This can be changed in the Inspector window
public Vector2 jumpForce = new Vector2(0, 300);
private bool shouldJump = true;
// Update is called once per frame
private float jumpThreshold = 0.5f;
private float previousJumpTime;
void FixedUpdate ()
{
// Jump
float mc = MicControl.loudness;
//Debug.Log (mc);
if (mc>1.3f && shouldJump)
{
shouldJump = false;
previousJumpTime = Time.time;
GetComponent<Rigidbody2D>().velocity = Vector2.zero;
GetComponent<Rigidbody2D>().AddForce(jumpForce);
}
if (!shouldJump)
{
if(Time.time-previousJumpTime>jumpThreshold)
{
shouldJump = true;
}
}
// Die by being off screen
Vector2 screenPosition = Camera.main.WorldToScreenPoint(transform.position);
if (screenPosition.y > Screen.height || screenPosition.y < 0)
{
Die();
}
}
// Die by collision
void OnCollisionEnter2D(Collision2D other)
{
Die();
}
void Die()
{
Application.LoadLevel ("main");
}
}

Answer 1

You said your level is called Main, but in the code you are loading "main", i'm not sure if that's the problem, but you seem to be loading the level correctly, so check if is main or Main the exact name of the level.
Also, when compiling, make sure you have all levels checked

Answer 2

With provided data its impossible to say what causes low performance, but I recommend you to use Profiler tool (can be found in personal version of Unity 5) and figure out what scripts and functions are problematic.
Also, try to avoid calling GetComponent<Rigidbody2D>() in Update/FixedUpdate/LateUpdate and cache this component instead.

Answer 3

I second what Utamaru said.
Rigidbody2D myRigidbody2d;
void Start ()
{
myRigidbody2d = GetComponent<Rigidbody2D>(); //Do this once
}
Inside your fixed update, you can do this:
void FixedUpdate ()
{
// Jump
float mc = MicControl.loudness;
//Debug.Log (mc);
if (mc>1.3f && shouldJump)
{
shouldJump = false;
previousJumpTime = Time.time;
myRigidbody2d.velocity = Vector2.zero;
myRigidbody2d.AddForce(jumpForce);
}
if (!shouldJump)
{
if(Time.time-previousJumpTime>jumpThreshold)
{
shouldJump = true;
}
}
// Die by being off screen
Vector2 screenPosition = Camera.main.WorldToScreenPoint(transform.position);
if (screenPosition.y > Screen.height || screenPosition.y < 0)
{
Die();
}
}
I can't see the rest of your code so I am not really sure that is the problem but give this a try.