Cannot delete admin user

File: Users.cshtml

Change line:
52. <td class="delete">@Html.ActionLink(SiteStrings.Navigation_Delete, "Delete", new

{ id = user.ExistingEmail }, new { @class = "confirm" })</td>
into:
52. <td class="delete">@Html.ActionLink(SiteStrings.Navigation_Delete, "DeleteUser", new { id = user.ExistingEmail }

, new

{ @class = "confirm" }

)</td>