allowdoubleescaping = "true" in IIS Express Config Not Working

Question

I get HTTP Error 404.11 - Not Found The request filtering module is configured to deny a request that contains a double escape sequence. Error when I send a request to a .razor page in Blazor, The link is dynamically built and sent to users email:

string confirmationLink = $"{HttpContext.Request.Scheme}://{Request.Host}/account/confirmemail/{System.Web.HttpUtility.UrlEncode(user.Id)}/{System.Web.HttpUtility.UrlEncode(confirmationToken)}";

I modified the IIS Express config files in five places:

• web.config in "C:\Windows\System32\inetsrv"
• applicationhost.config in "C:\Program Files\IIS Express\AppServer"
• applicationhost.config in "C:\Program Files\IIS Express\config\templates\PersonalWebServer"
• applicationhost.config in "C:\Program Files (x86)\IISExpress\AppServer"
• applicationhost.config in "C:\Program Files(x86)\IIS Express\config\templates\PersonalWebServer"

In all cases I modified the

<requestFiltering allowDoubleEscaping="true">

tag in "web.server" "security" section. But I still get the error. Is there any solution to this?

Answer 1

This worked for me...

1. To find the applicationhost.config file for IISExpress I looked for the IIS Express icon in the system tray (lower right corner of Windows 10).
2. I right-clicked on the IIS Express icon and clicked "Show All Applications".
3. From the list of Running Applications I clicked on the Site Name whose config file I wanted to modify.
4. Once the site name was clicked the word Config: appeared below.
5. I clicked on the path to the right of Config: This opened the applicationhost.config file in Visual Studio.
6. There I clicked Ctrl-F and searched for <requestFiltering> which I changed to <requestFiltering allowDoubleEscaping="true">