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

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">