FileObserver does not work on external storage in Android 6.0 Marshmallow (API 23)

Question

I have an app that observes a public directory on external storage with FileObserver. It works fine on Lollipop devices. I want to add support for

Answer 1

This appears to be a bug in Marshmallow, see this link.

This is not fixed even in Nougat, you could get rid of the API this whole FileObserver, as it makes completely useless the fact that on most of the devices, it will not work.