Popup doesn't find Index page after save

Question

First of all I want to say that I'm a total noob when it comes to working with javascript, and it's my first time when I'm using popup in a project.

I did this until now (Index view):

<button type="button" class="btn btn-info btn-xs" data-toggle="modal" data-target="#enquirypopup">Add Event</button>//Table with the list of entries.
<div id="enquirypopup" class="modal fade in" role="dialog" tabindex="-1">
    <div class="modal-dialog">

        <!-- Modal content-->
        <div class="modal-content row">
            <div class="modal-header custom-modal-header">
                <button type="button" class="close" data-dismiss="modal">×</button>
                <h4 class="modal-title">Add Event</h4>
            </div>
            <div class="modal-body">
            //This is only a bit off what I have tried
                @*<form name="info_form" class="form-inline" action="#" method="post">*@
                @*<form name="info_form" class="form-inline" action="Project/Areas/User/Events/Add" method="post">*@
                @*<form name="info_form" class="form-inline" action="@Url.Action("Index", "Events")" method="post">*@
                @*<form name="info_form" class="form-inline" action="@Url.Action("Add")" method="post">*@
                
                <form name="info_form" class="form-inline" action="/Events/Add" method="post">
                    <div class="form-group col-sm-12">
                        <label>Event Title: </label>
                        <br />
                        <input type="text" class="form-control" name="Event" id="Event" placeholder="Event Name">
                    </div>
                    <br />
                    <br />
                    <div class="form-group col-sm-12">
                        <label>Starting Date and Time: </label>
                        <br />
                        <input type="text" class="form-control" name="Start_Date" id="Start_Date" placeholder="ll/zz/aaaa hh:mm:ss">
                    </div>
                    <br />
                    <br />
                    <div class="form-group col-sm-12">
                        <label>Ending Date and Time: </label>
                        <br />
                        <input type="text" class="form-control" name="End_Date" id="End_Date" placeholder="ll/zz/aaaa hh:mm:ss">
                    </div>
                    <br />
                    <br />
                    <div class="modal-footer">
                        @*<div class="form-group col-sm-12">*@
                        <button type="submit" class="btn btn-success pull-right">Save</button>
                        @*</div>*@
                    </div>
                </form>
            </div>

        </div>

    </div>
</div>

And here is the controller:

public ActionResult Index()
    {
        return View(db.tbl_Event.ToList());
    }

[HttpGet]
    //public PartialViewResult Add()
    public ActionResult Add()
    {
        //return PartialView("_Event");
        return View();
    }

    [HttpPost]
    //public PartialViewResult Add(BOL3.tbl_Event eve)
    public ActionResult Add(BOL3.tbl_Event eve)
    {
        db.tbl_Event.Add(eve);
        db.SaveChanges();

        //return Add();
        //return View("Index");
        //return View();
        return RedirectToAction("Index", eve);
    }

When I Save the entered data into the popup, it shows error: "The view 'Index' or its master was not found or no view engine supports the searched locations. The following locations were searched: bla/bla/bla", but it doesn't show the corect path to the index view. So that is my problem, when I save the data I want to close the popup and the value to be displayed in the list(Index view). Please help me with this, because I have searched many websites to help me do this but nothing worked for me.