Error using paperclip gem in ruby on rails

Question

I wanted to upload image (using paperclip gem) to my product in my rails project, so i watched a youtube video how to do it (https://www.youtube.com/watch?v=Z5W-Y3aROVE) I did all he did, but i when i add a new product i get an error -

'New Product

2 errors prohibited this product from being saved:

Img url Paperclip::Errors::NotIdentifiedByImageMagickError

Img url has contents that are not what they are reported to be' , right above my new product form how do i fix it.

MY PRODUCT MODEL

class Product < ActiveRecord::Base
    belongs_to :user
    has_many :taggings, dependent: :destroy
    has_many :tags, through: :taggings

    has_attached_file :img_url, styles: { large: "800x600>", medium: "320x200>", thumb: "100x80#" }
    validates_attachment_content_type :img_url, content_type: /\Aimage\/.*\z/

    def self.tagged_with(name)
        Tag.find_by!(name: name).products
    end

    def all_tags=(names)
        # names="music, spotify"
        self.tags = names.split(',').map do |name|
            Tag.where(name: name).first_or_create!
        end
    end
    def all_tags
        tags.map(&:name).join(", ")
    end
end

MY PRODUCTS_CONTROLLER

class ProductsController < ApplicationController
  # before_action :authenticate_user!
  before_action :set_product, only: [:show, :edit, :update, :destroy]

  # GET /products
  # GET /products.json
  def index
     if params[:tag]
    @products = Product.tagged_with(params[:tag])
  else
    @products = Product.all
  end
  end

  # GET /products/1
  # GET /products/1.json
  def show
  end

  # GET /products/new
  def new
    @product = Product.new
  end

  # GET /products/1/edit
  def edit
  end

  # POST /products
  # POST /products.json
  def create
    @product = current_user.products.new(product_params)

    respond_to do |format|
      if @product.save
        format.html { redirect_to @product, notice: 'Product was successfully created.' }
        format.json { render :show, status: :created, location: @product }
      else
        format.html { render :new }
        format.json { render json: @product.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /products/1
  # PATCH/PUT /products/1.json
  def update
    respond_to do |format|
      if @product.update(product_params)
        format.html { redirect_to @product, notice: 'Product was successfully updated.' }
        format.json { render :show, status: :ok, location: @product }
      else
        format.html { render :edit }
        format.json { render json: @product.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /products/1
  # DELETE /products/1.json
  def destroy
    @product.destroy
    respond_to do |format|
      format.html { redirect_to products_url, notice: 'Product was successfully destroyed.' }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_product
      @product = current_user.products.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def product_params
      params.require(:product).permit(:filetype, :title, :img_url, :description, :all_tags, :price, :uploaded_by, :tutorial_url)
    end
end

and i displayed my images as

<%= link_to image_tag(product.img_url.url(:medium), :class =>"img-fluid tm-img"),product%>