System.Web.HttpException (0x80004005): Error executing child request for handler 'System.Web.Mvc.HttpHandlerUtil+ServerExecuteHttpHandlerAsyncWrapper'. ---> System.ArgumentNullException: Value cannot be null.
Parameter name: mediaItem
   at Umbraco.Web.ImageCropperTemplateExtensions.GetCropUrl(IPublishedContent mediaItem, Nullable`1 width, Nullable`1 height, String propertyAlias, String cropAlias, Nullable`1 quality, Nullable`1 imageCropMode, Nullable`1 imageCropAnchor, Boolean preferFocalPoint, Boolean useCropDimensions, Boolean cacheBuster, String furtherOptions, Nullable`1 ratioMode, Boolean upScale)
   at Slimsy.Slimsy.ConvertImgToSrcSet(HtmlHelper htmlHelper, String html, Boolean generateLqip, Boolean removeStyleAttribute, Boolean removeUdiAttribute, Boolean roundWidthHeight)
   at Slimsy.Slimsy.ConvertImgToSrcSet(HtmlHelper htmlHelper, IHtmlString html, Boolean generateLqip, Boolean removeStyleAttribute, Boolean removeUdiAttribute)
   at ASP._Page_Views_dmo_grid_editors_tabs_cshtml.Execute() in D:\wwwroot\dmo-gtp\wwwroot\Views\dmo\grid\editors\tabs.cshtml:line 48
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.ViewResultBase.ExecuteResult(ControllerContext context)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultFilterRecursive(IList`1 filters, Int32 filterIndex, ResultExecutingContext preContext, ControllerContext controllerContext, ActionResult actionResult)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionResultWithFilters(ControllerContext controllerContext, IList`1 filters, ActionResult actionResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass3_1.<BeginInvokeAction>b__1(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult)
   at System.Web.Mvc.Controller.<>c.<BeginExecuteCore>b__152_1(IAsyncResult asyncResult, ExecuteCoreState innerState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult)
   at System.Web.Mvc.MvcHandler.<>c.<BeginProcessRequest>b__20_1(IAsyncResult asyncResult, ProcessRequestState innerState)
   at System.Web.Mvc.Async.AsyncResultWrapper.WrappedAsyncVoid`1.CallEndDelegate(IAsyncResult asyncResult)
   at System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult)
   at System.Web.Mvc.HttpHandlerUtil.ServerExecuteHttpHandlerWrapper.<>c__DisplayClass5_0.<Wrap>b__0()
   at System.Web.Mvc.HttpHandlerUtil.ServerExecuteHttpHandlerWrapper.Wrap[TResult](Func`1 func)
   at System.Web.HttpServerUtility.ExecuteInternal(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage, VirtualPath path, VirtualPath filePath, String physPath, Exception error, String queryStringOverride)
   at System.Web.HttpServerUtility.ExecuteInternal(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage, VirtualPath path, VirtualPath filePath, String physPath, Exception error, String queryStringOverride)
   at System.Web.HttpServerUtility.Execute(IHttpHandler handler, TextWriter writer, Boolean preserveForm, Boolean setPreviousPage)
   at System.Web.HttpServerUtility.Execute(IHttpHandler handler, TextWriter writer, Boolean preserveForm)
   at System.Web.Mvc.Html.ChildActionExtensions.ActionHelper(HtmlHelper htmlHelper, String actionName, String controllerName, RouteValueDictionary routeValues, TextWriter textWriter)
   at System.Web.Mvc.Html.ChildActionExtensions.Action(HtmlHelper htmlHelper, String actionName, String controllerName, RouteValueDictionary routeValues)
   at Our.Umbraco.DocTypeGridEditor.Web.Extensions.HtmlHelperExtensions.RenderDocTypeGridEditorItem(HtmlHelper helper, IPublishedContent content, String editorAlias, String viewPath, String previewViewPath, Boolean isPreview)
   at ASP._Page_app_plugins_doctypegrideditor_render_DocTypeGridEditor_cshtml.Execute() in D:\wwwroot\dmo-gtp\wwwroot\app_plugins\doctypegrideditor\render\DocTypeGridEditor.cshtml:line 28
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy()
   at System.Web.Mvc.WebViewPage.ExecutePageHierarchy()
   at System.Web.WebPages.WebPageBase.ExecutePageHierarchy(WebPageContext pageContext, TextWriter writer, WebPageRenderingBase startPage)
   at Umbraco.Core.Profiling.ProfilingView.Render(ViewContext viewContext, TextWriter writer)
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at ASP._Page_Views_Partials_grid_editors_DMOBase_cshtml.Execute() in D:\wwwroot\dmo-gtp\wwwroot\Views\Partials\grid\editors\DMOBase.cshtml:line 20