Adsense says ads.txt "Not found", but it's definitely there

Question

Google has been saying it can't find ads.txt for a long time, but the page is there.

ads.txt is accessible over http, https, and without a defined protocol. It is also accessible with or without www.

Google even says it has crawled the page, but somehow says it can't find it.

What else could be the problem here?

Answer 1

Try the official Ads.txt troubleshooter. https://support.google.com/adsense/answer/12171244

If you click on the Ads.txt troubleshooter Button, it will guide you step-by-step on how to fix your particular situation

Answer 2

I had a similar problem. Now resolved. Using Apache.

In my case, I had a Redirect permanent in the type :80 (http) virtual host, so that ALL requests for http files were served via a type :443 (https) virtual host.

I've now changed this so that requests for two specific http files (ads.txt and favicon.ico) are excluded from redirection.

I've also reinstated an actual directory for the ads.txt and favicon.ico files.

<VirtualHost xxx.xxx.xxx.xxx:80>
   ServerName example.com
   ServerAlias www.example.com
   DocumentRoot "/var/www/exampledirectory/html"
   <Directory "/var/www/exampledirectory/html">
      Require all granted
   </Directory>
   RewriteEngine on
   RewriteCond %{REQUEST_URI} !=/ads.txt
   RewriteCond %{REQUEST_URI} !=/favicon.ico
   RewriteRule (.*) https://www.example.com/$1 [R=301,L]
</VirtualHost>

I am not sure what was the root cause of my problem but I suspect that Google requested the http version and my server response was 301 and thus not a 'standard relative path', and so, quite correctly, failed the ads.txt validation.