HTTP Error 404.3 - Not Found - backend .net core, frontend react hosted on azure app service

Question

HTTP Error 404.3 - Not Found The page you are requesting cannot be served because of the extension configuration. If the page is a script, add a handler. If the file should be downloaded, add a MIME map.

I got this error when accessing react frontend. the app is hosted on the azure app service. so anyone knows how to fix this? is it need to be done in react side?

Answer 1

HTTP Error 404.3 - Not Found

• It could be because you have not installed aspnet_regiis.exe

• This will register your .NET framework for you and should solve the problem.

Most likely causes: •It is possible that a handler mapping is missing. By default, the static file handler processes all content.
•The feature you are trying to use may not be installed.
•The appropriate MIME map is not enabled for the Web site or application. (Warning: Do not create a MIME map for content that users should not download, such as .ASPX pages or .config files.)

Things you can try:
•In system.webServer/handlers: ◦Ensure that the expected handler for the current page is mapped.

If the page is a script, add a handler. If the file should be downloaded, add a MIME map.

Add the below snippet in web.config in configuration section -- ><system.webServer> tag

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <system.webServer>
        <staticContent>
            <remove fileExtension="woff"/>
            <mimeMap fileExtension="woff" mimeType="application/font-woff" />
            <remove fileExtension="woff2"/>
            <mimeMap fileExtension="woff2" mimeType="application/font-woff" />
            <remove fileExtension=".json"/>
            <mimeMap fileExtension=".json" mimeType="application/json" />
            <remove fileExtension=".svg"/>
            <mimeMap fileExtension=".svg" mimeType="image/svg+xml" />
         </staticContent>
    </system.webServer>
</configuration>

• Add the text allowPathInfo="true" after the word “unspecified”

Please refer Adding Static Content MIME Mappings and HTTP Error 404.3 - Not Found for more details