Sierra by Newmark Homes

System.NullReferenceException: Object reference not set to an instance of an object.
   at ASP._Page_Views_Partials_Grid_Editors_DocTypeGridEditor_GalleryPreview_cshtml.Execute() in C:\inetpub\wwwroot\Brookfield Residential\Views\Partials\Grid\Editors\DocTypeGridEditor\GalleryPreview.cshtml:line 7
   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.Web.Mvc.ProfilingView.Render(ViewContext viewContext, TextWriter writer) in D:\a\1\s\src\Umbraco.Web\Mvc\ProfilingView.cs:line 25
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at Our.Umbraco.DocTypeGridEditor.Web.Extensions.HtmlHelperExtensions.RenderDocTypeGridEditorItem(HtmlHelper helper, IPublishedElement content, String editorAlias, String viewPath, String previewViewPath, Boolean isPreview)
   at ASP._Page_app_plugins_doctypegrideditor_render_DocTypeGridEditor_cshtml.Execute() in C:\inetpub\wwwroot\Brookfield Residential\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.Web.Mvc.ProfilingView.Render(ViewContext viewContext, TextWriter writer) in D:\a\1\s\src\Umbraco.Web\Mvc\ProfilingView.cs:line 25
   at System.Web.Mvc.Html.PartialExtensions.Partial(HtmlHelper htmlHelper, String partialViewName, Object model, ViewDataDictionary viewData)
   at ASP._Page_Views_Partials_grid_editors_Base_cshtml.Execute() in C:\inetpub\wwwroot\Brookfield Residential\Views\Partials\grid\editors\Base.cshtml:line 21