Enable double escape sequences in Windows Server !

Cause

The HTTP request to the Web server contains a double escape sequence. However, the Request Filtering feature is configured so that the Web server denies double escape sequences.

Resolution

To resolve this problem, follow these steps.
  1. Click Start, click Run, and then type cmd in the Open box.
  2. Type the following command, and then press ENTER:

    C: CD %windir%\system32\inetsrv

     

  3. Run one of the following commands: 
    • Appcmd set config "Default Web Site" /section:system.webServer/Security/requestFiltering -allowDoubleEscaping:True

      Note This will configure this setting only for the “Default Web Site” by creating or editing the Web.config file in the root folder of the “Default Web Site.”

    • appcmd set config "Default Web Site" /section:system.webServer/Security/requestFiltering -allowDoubleEscaping:True /commit:appHost

      Note This will configure this setting only for the “Default Web Site” in the applicationHost.config file by using a location tag.