Error: The request filtering module is configured to deny a request that contains a double escape sequence in ASP.Net

Hi nedash,

I have created sample code which fullfill your requirement.

HTML

Default.aspx

<div>
    <asp:TextBox ID="txtsearch" runat="server" />
    <asp:Button ID="btnSubmit" OnClick="OnClick" Text="Image" runat="server" />
</div>

C#

protected void OnClick(object sender, EventArgs e)
{
    Response.Redirect("Search/" + txtsearch.Text.Trim());
}

Search.aspx

<div>
    <asp:Label ID="lblSearchText" runat="server" />
</div>

C#

protected void Page_Load(object sender, EventArgs e)
{
    lblSearchText.Text = this.Page.RouteData.Values["SearchText"].ToString();
}

Global.asax

void Application_Start(object sender, EventArgs e)
{
    RegisterRoutes(System.Web.Routing.RouteTable.Routes);
}

static void RegisterRoutes(System.Web.Routing.RouteCollection routes)
{
    routes.MapPageRoute("Search", "Search/{SearchText}", "~/Search.aspx");
}

Web.config

  <configuration>
  <system.web>
    <compilation debug="true" targetFramework="4.0"/>
  </system.web>
  <system.webServer>
    <security>
      <requestFiltering allowDoubleEscaping="true"/>
    </security>
  </system.webServer>
</configuration>

Screenshot