Moodle 3.1.1+ (build 20161817). Use Flavours to capture a slew of Adaptable theme settings from a test server.
The Flavour was successfully created and downloaded.
But on target server – with EXACTLY the same codebase (and database) – I get:

1. Flavours Deployment - Ingredients previsualization
   • Step 2 - Ingredients previsualization
   • Warning : All Adaptable settings will be overwritten (which is what I want!)
2. Hit [Deploy]. Success
3. [Continue to Notifications]
4. Site Admin > Purge all caches
5. No changes saved!

There are no php errors thrown (I have error reporting switched on).
Admin_presets is not a solution – it does not work with Moodle v3.x.