Use of contain non-ASCII characters like à, è, ù in an IIS URL

Allow High Bit Characters in IIS

This feature either allows or rejects all requests to IIS that contain non-ASCII characters. The UrlScan equivalent is AllowHighBitCharacters.

Reference: https://docs.microsoft.com/en-us/iis/manage/configuring-security/use-request-filtering

There are two approaches to achieve this 

Suppose you want to allow high bit characters for entire server. Then follow below steps: 

1. Click on Request filtering 

2. Then go to Edit feature settings 

3. Tick the allow high-bit characters 

Suppose you want to allow high bit characters for one application but not for the entire server.

Set the allowHighBitCharacters="false" in the ApplicationHost.config file; but within the application root, create a Web.config file that allows that single application to accept non-ASCII characters. In the Web.config file, use:

<configuration> <system.webServer> <security> <requestFiltering allowHighBitCharacters="true" > </requestFiltering> </security> </system.webServer> </configuration>