I have implemented platform-specific pages for Android and iOS to allow a user to select a file to use within my app. In the Android version, everything works as expected on my Samsung Galaxy Note 4 until I select a file from DropBox (I am using the Dropbox Dropin component). As soon as I select a file I get "An Unexpected Error Occurred". I have not yet completed my iPhone implementation to see if it suffers from the same issue.
I have attached a very simple app that suffers from the same issue. One other note is that my OnActivityResult() implementation is currently in the MainActivity since this is not available in my platform-specific page.