Player is floating away... Whaa...

So I opened a old project in Unity 4.6 and the project was made in 4.3. I just noticed my player started floating away. It just floats upwards and just keeps going. There is nothing I can do. I tried invert the gravity from -9.81 to 300 and now the player is not moving up or down. What is this?! There is nothing in the code that does this.

The whole player script. (2D Player).

 using UnityEngine;
 using System.Collections;
 
 [System.Serializable]
 public class Movement{
     public float speed = 5.0f;
     public float jumpForce = 10.0f;
 }
 
 [System.Serializable]
 public class AnimatorSettings{
     public string movingValue = "Speed";
     public string jumpingValue = "Grounded";
     public string verticalSpeedValue = "vSpeed";
 }
 
 [System.Serializable]
 public class SoundEffects{
     public GameObject jumpSound;
     public GameObject dieSound;
 }
 
 [RequireComponent(typeof(Rigidbody2D))]
 [RequireComponent(typeof(BoxCollider2D))]
 public class PlayerController : MonoBehaviour {
 
     public Movement movement;
     public AnimatorSettings animatorSettings;
     public SoundEffects soundEffects;
 
     bool facingRight = true;
 
     Rigidbody2D rig;
     Animator anim;
     TrailRenderer trail;
 
     public bool grounded = false;
 
     public LayerMask groundLayer;
 
     RaycastHit2D hit;
 
     void Start(){
         rig = GetComponent<Rigidbody2D>();
         anim = GetComponent<Animator>();
         trail = GetComponent<TrailRenderer>();
 
         rig.fixedAngle = true;
         trail.enabled = false;
     }
 
     void Update(){
         if(grounded && Input.GetButtonDown ("Jump")){
             anim.SetBool(animatorSettings.jumpingValue, false);
             rig.AddForce(new Vector2(0, movement.jumpForce * 10));
             Instantiate(soundEffects.jumpSound, Vector3.zero, Quaternion.identity);
         }
 
         if(Physics2D.Raycast(transform.position, -Vector2.up, 0.18f, groundLayer)){
             grounded = true;
         } else {
             grounded = false;
         }
     }
 
     void FixedUpdate(){
         anim.SetBool(animatorSettings.jumpingValue, grounded);
 
         anim.SetFloat (animatorSettings.verticalSpeedValue, rig.velocity.y);
 
         float move = Input.GetAxis("Horizontal");
 
         anim.SetFloat(animatorSettings.movingValue, Mathf.Abs(move));
 
         rig.velocity = new Vector2(move * movement.speed, rig.velocity.y);
 
         if(move > 0 && !facingRight){
             Flip();
         } else if(move < 0 && facingRight){
             Flip ();
         }
     }
 
     void Flip(){
         facingRight = !facingRight;
         Vector3 theScale = transform.localScale;
         theScale.x *= -1;
         transform.localScale = theScale;
     }
 }