[Solved] asp.net mvc grid custom command errors

[J]

I am tying to implement the custom command like in this demo.
Instead of opening the details in a popup form, I would like to redirect to the standard details view.
When I return the details view I get the error "'hr' undefined"

My view-code:

@(Html.Telerik().Grid(Model)
    .Name("Grid")
    .Columns(columns =>
    {
        columns.Bound(o => o.clientnr).Width(100);
        columns.Bound(o => o.naam).Width(200);
        columns.Bound(o => o.geboortedatum).Format("{0:dd-MM-yyyy}").Width(120);
        columns.Command(commands =>
            commands.Custom("viewDetails")
            .Text("Details")
            .DataRouteValues(route => route.Add(o => o.clientnr).RouteKey("clientnr"))
            .Ajax(true)
            .Action("ViewDetails", "Home"))
            .HtmlAttributes(new { style = "text-align: center" }).Width(150);
    })
    .DataBinding(dataBinding =>
    {
        dataBinding.Ajax().Select("_Index", "Home").Enabled(true).OperationMode(GridOperationMode.Client);
    })
    .Selectable()
    .Scrollable(scrolling => scrolling.Enabled(true))
    .Sortable(sorting => sorting.Enabled(true))
    .Pageable(paging => paging.Enabled(true))
    .Filterable(filtering => filtering.Enabled(true))
    .Groupable(grouping => grouping.Enabled(true))
    .Footer(true)
    .ClientEvents(events => events.OnRowDataBound("onRowDataBound"))
)

And the controler:

public ViewResult ViewDetails(int clientnr)
        {
            var details = GetClientViewModel().FirstOrDefault(o => o.clientnr == clientnr);
            return View("Details", details);
        }

Also tried a redirect to route:

public ActionResult ViewDetails(int clientnr)
        {
            return RedirectToRoute("OpenDetails", clientnr);
        }

It's giving me the "Internal server error"

I also can't get into the clientside function onComplete() method.

Can someone help me out with a working solution?
Thanks in advance.