The ViewFormPagesLockDown Feature (Site Collection) in SharePoint 2013 is activated and visible by default. This is not the case for previous SharePoint versions.
If you enable anonymous access to your site (or parts of it), you still need to deactivate this feature if you want those users to be able to dive into Lists or Libraries.
- Enable anonymous access in “Authentication Providers” (Central Administration > Application Management)
- Grant rights to anonymous users in “Site permissions”
- Grant rights to specific library (if applicable)
- Disable the “Limited-access user permission lockdown mode” Site Collection Feature (if applicable)
I’ve just spent the better half of the day troubleshooting this issue because it didn’t happen with a SharePoint 2010 upgraded Site Collection (because the feature is disabled by default), but was occurring on newly created SharePoint 2013 Site Collections.
Lesson learned.