I am attempting to get a partial view macro to work. But it doesn't.

My Model is EF6 so I don't know exactly how to paste it in here, but here is the specific table I am referencing. The context name is "WebSubscriptionsEntities":

    namespace Bridge.Models
    {
        using System;
        using System.Collections.Generic;

        public partial class SubscriptionItem
        {
            public int SubItemID { get; set; }
            public string title { get; set; }
            public Nullable<System.DateTime> post_date { get; set; }
            public string filename { get; set; }
            public Nullable<bool> active { get; set; }
            public string SubID { get; set; }
            public string posted_by { get; set; }
            public string pr_category_type { get; set; }
            public Nullable<System.DateTime> last_modified_date { get; set; }
            public string Last_modified_by { get; set; }
            public Nullable<int> PressReleaseID { get; set; }
        }

}

My Controller (WebSubscriptionsItemListController.cs):

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Bridge.Models;

namespace Bridge.Controllers
{
    public class WebSubscriptionsItemListController : Controller
    {
        // GET: WebSubscriptionsItemList
        public ActionResult GetSubscriptionItems()
        {
            List<SubscriptionItem> subItems = GetItems();

            return PartialView("WebSubscriptionItemList", subItems);
        }

        public List<SubscriptionItem> GetItems()
        {
            using (WebSubscriptionsEntities dc = new WebSubscriptionsEntities())
            {
                List<SubscriptionItem> itms = dc.SubscriptionItems.Where(x => x.SubID == "31").OrderByDescending(x => x.post_date).ToList();

                return itms;
            }
        }
    }
}

My Partial View (WebSubscriptionsItemList.cshtml):

@model List<Bridge.Models.SubscriptionItem>

    <link rel="stylesheet" type="text/css" href="/lib/DataTables/datatables.min.css" />

    <div>

        <table id="PRs" class="table table-striped table-bordered table-hover w-100">
            <thead>
                <tr>
                    <th scope="col">Date</th>
                    <th scope="col">Title</th>
                </tr>
            </thead>
            <tbody>
                @foreach (var itm in Model)
                {
                <tr>
                    <td>@itm.post_date</td>
                    <td>@itm.title</td>
                </tr>
                }
            </tbody>
        </table>

    </div>

    <script type="text/javascript" src="/lib/DataTables/datatables.min.js"></script>
    <script>
    $(document).ready(function () {
        $('#PRs').DataTable();
    });
    </script>

My Partial View Macro (WebSubscriptionsItemList.cshtml):

@inherits Umbraco.Web.Macros.PartialViewMacroPage
@using Bridge.Models;

@Html.Action("GetSubscriptionItems", "WebSubscriptionsItemList")

The error I get is:

System.InvalidOperationException: No route in the route table matches the supplied values.