c# – Selecting an image stops Visual Studio debugging

I am following a tutorial and I am stuck

I am trying to upload an image using C# MVC. Although the issue appears to be only in the HTML.

My HTML is

    <form action="/Admin/UploadImage/" enctype="multipart/form-data" onsubmit="AJAXSubmit(this);return false;" method="post">
        <dl>
            <dt>
                <label for="FileUpload_FormFile">File</label>
            </dt>
            <dd>
                <input id="FileUpload_FormFile" type="file"
                       name="FileUpload.FormFile" />
            </dd>
        </dl>

        <input class="btn" type="submit" value="Upload" />

        <div style="margin-top:15px">
            <output name="result"></output>
        </div>
    </form>

If I click the Choose File option and select an JPG image, Visual Studio stops. I don’t even click the submit button!! I have to reclick the start button in visual studio to restart IIS-Express. And this issue occurs every time I chose an image to upload!

The same issue happens with jpg, png (even small files of 50kb)

Because of this I don’t see any error message or exception.

I’m totally lost. I don’t know how to progress this at all