Files Connect settings are unavailable in Setup
|Knowledge Article Number||000227254|
|Description||The settings for Files Connect are normally found in the Setup menu under Customize | Salesforce Files | Settings | Files Connect
However, a known bug prevents them from being displayed if the org has been switched from Professional to Enterprise Edition.
|Resolution||Make sure all Files Connect related Blacktab permissions are activated, as per this article: Files Connect activation in Blacktab|