When in admin the WP functionality fails

While I was posting this I figured out what the problem is 🙂 But I will place the problem here if anyone has the same problem.

The problem was the .htaccess file in the plugins directory.
The .htaccess file had some 404 directive written. I deleted it and everything is fine now.

When I am in the admin of my WP site some plugin icons and some other files don’t work properly.

Files ARE there on the server. When I try to see them in the browser I get a 404 page. What can this be? Is this a CHMOD problem?

Thanks.