Successful login with 'requireLogin' redirects to 404.shtml

Question

I have recently migrated an intranet to its production environment, and the requireLogin is misbehaving:

1. I'd go to intranet.example.com/
2. Log in with my details
3. Craft will redirect me to intranet.example.com/404.shtml, showing 'Layout file - This content should not be seen.'
   • this page doesn't exist, and I can't find any reference to 404.shtml on any page.
4. If I reload intranet.example.com/, it will show me the homepage, logged in. It works fine after that
5. I can log out and in again, it will work fine. I need to log out, close the browser and log in again to replicate the error

I have no redirects or have changed anything on the Craft config. Basically is a default 2.5 installation with new templates.

It works fine both locally (MAMP) and on my dev environment, but not on the server I just migrated it to.

Answer 1

I checked the http headers, and apparently my server was redirecting to a 404 page because the favicon.ico was missing.

As soon as I uploaded one it all worked fine again.