Hi Matt,

There are a couple of mistakes in your code and you should fix them.

Let's discuss the RenderPageLink method first. As the error says and Sibren mentioned before, PublishedContent does not contain a definition for any (which is correct, because it's a single item). You can use the .Any method on collections. In this case at most you can add a null check. Your method should look like the code below.

@helper RenderPageLink(IPublishedContent item)
{
    //Check if item not is null
    if (item !=  null)
    {
        // Render url for each child page
        foreach (var child in item.Children())
        {
            <a href="@child.Url" class="drop-down-link w-dropdown-link">@child.Name</a>
        }
    }
}

Correct me if I'm wrong but I expect that you want to check if a navigation page has children and if so you want to show a link for each of them and if not you want to show the link of the navigation page itself? You can achieve this by doing something like this:

 @foreach (var page in navigationPages)
 {
     //We need to check if this has children or not
     if (page.Children.Any())
     {
         <div data-hover="1" data-delay="0" class="drop-down-menu w-dropdown">
             <div class="nav-link w-dropdown-toggle">
                 <a href="@page.Url" class="link-dropdown">
                     <div>@page.Name</div>
                 </a>
             </div>
             <nav class="w-dropdown-list">
                 @foreach (var child in page.Children())
                 {
                     @RenderPageLink(child)
                 }
             </nav>
          </div>
       }
       else
       {
           <a href="@page.Url" class="nav-link w-nav-link">@page.Name</a>
       }
  }

The full code should look something like this.

@inherits Umbraco.Web.Mvc.UmbracoViewPage
@{    
        IPublishedContent homePage = Model.Root();
        IEnumerable<IPublishedContent> navigationPages = homePage.Children(x => x.IsVisible());
}




<div data-collapse="medium" data-animation="default" data-duration="400" class="navbar w-nav">
    <div class="nav-container w-container">
        <nav role="navigation" class="nav-menu w-nav-menu">
            @* //The top level requires different rendering to children so let us split it up. *@
            @foreach (var page in navigationPages)
            {
                //We need to check if this has children or not
                if (page.Children.Any())
                {
                    <div data-hover="1" data-delay="0" class="drop-down-menu w-dropdown">
                        <div class="nav-link w-dropdown-toggle">
                            <a href="@page.Url" class="link-dropdown">
                                <div>@page.Name</div>
                            </a>
                        </div>
                        <nav class="w-dropdown-list">
                            @foreach (var child in page.Children())
                            {
                                @RenderPageLink(child)

                            }

                        </nav>
                    </div>
                }
                else
                {
                    <a href="@page.Url" class="nav-link w-nav-link">@page.Name</a>
                }
            }
        </nav>
        <div class="menu-button w-nav-button">
            <div class="mobile-icon w-icon-nav-menu"></div>
        </div>
    </div>
</div>

@helper RenderPageLink(IPublishedContent item)
{
    //Check if item not is null
    if (item !=  null)
    {
        // Render url for each child page
        foreach (var child in item.Children())
        {
            <a href="@child.Url" class="drop-down-link w-dropdown-link">@child.Name</a>
        }
    }
}