title: Warning: Each child in a list should have a unique "key" prop. React table
body: <p>I am getting this warning and I don't know how to solve it. I think it has to be with react-tables-2, the complete warning says this:</p>
  
  <pre><code>index.js:1375 Warning: Each child in a list should have a unique "key" prop. See..
  in Cell (created by ReactTable)
  in div (created by TdComponent)
  in TdComponent (created by ReactTable)
  in div (created by TrComponent)
  in TrComponent (created by ReactTable)
  in div (created by TrGroupComponent)
  in TrGroupComponent (created by ReactTable)
  in div (created by Tbody)
  in Tbody (created by ReactTable)
  in div (created by TableComponent)
  in TableComponent (created by ReactTable)
  in div (created by ReactTable)
  in ReactTable (at CustomReactTable.js:106)
  in div (at CustomReactTable.js:99)
  in CustomReactTable (created by Context.Consumer)
  in withRouter(CustomReactTable) (at ProductIndexComponent.js:69)
  in div (at ProductIndexComponent.js:68)
  in ProductIndexComponent (created by Context.Consumer)
  in withRouter(ProductIndexComponent) (created by Context.Consumer)
  in Route (at Wrapper.js:38)
  in div (created by Sidebar)
  in div (created by Sidebar)
  in Sidebar (at SideBar.js:62)
  in div (at SideBar.js:61)
  in SideBar (created by Context.Consumer)
  in withRouter(SideBar) (at Wrapper.js:36)
  in div (at AuthenticatedComponent.js:33)
  in AuthenticatedComponent (created by Context.Consumer)
  in withRouter(AuthenticatedComponent) (at Wrapper.js:35)
  in div (at Wrapper.js:34)
  in Wrapper (created by Context.Consumer)
  in Route (at App.js:28)
  in Switch (at App.js:26)
  in Router (created by BrowserRouter)
  in BrowserRouter (at App.js:25)
  in div (at App.js:24)
  in App (at src/index.js:10)
  </code></pre>
  
  <p>I have this warning twice in my console, and I've checked and tried to use the keys but it is not working, does anyone know what should I do to get rid of this warning?</p>
  
  <p>Edit: 
  this is the render method of the general table, and then I use this component for every table I need, for example, ProductTable, and I call this component.</p>
  
  <pre><code>render() {
  return (
    &lt;div className='main-content'&gt;
      {this.state.showDelete &amp;&amp; (
        &lt;DeleteComponent onCancelDeleteClick={this.onCancelDeleteClick} item={this.state.item} /&gt;
      )}
      &lt;h3&gt;{this.props.modelName}&lt;/h3&gt;
      {this.loadAddButton()}
      {this.loadFunctionalities()}
      &lt;ReactTable
        data={this.state.data}
        columns={this.props.columns}
        manual
        onFetchData={this.onFetchData}
        pages={this.state.pages}
      &gt;
      &lt;/ReactTable&gt;
      &lt;div className="total-records-tag"&gt;{this.props.modelName}: {this.state.totalItems}&lt;/div&gt;
    &lt;/div &gt;
  )
  </code></pre>
  
  <p>}
    }</p>
  
  <p>ProductComponent render method</p>
  
  <pre><code>  render() {
  return (
    &lt;div className='main-content'&gt;
      &lt;CustomReactTable columns={this.state.columns} modelName={"Products"} /&gt;
    &lt;/div &gt;
  )
  </code></pre>
  
  <p>}</p>