i’m trying to create a url string that works like this:
/app/process/example.com/index.html
so in other words,
/app/process
I think the error message you are getting is not from codeigniter but from your web server.
I replicated this using Apache2 without even using CodeIgniter: I created a file index.php, and then accessed index.php/a/b/c - it worked fine. If I then tried to access index.php/a/b/c%2F I got a 404 from Apache.
I solved it by adding to my Apache configuration:
AllowEncodedSlashes On
See the documentation for more information
Once you've done this you might need to fiddle around with $config['permitted_uri_chars'] in codeigniter if it is still not working - you may find the slashes get filtered out