I still experience exactly the error that is described here: Connecting SoundCloud to Facebook does not work in iOS .
My application is built in Adobe AIR. The application name is CloudDeck (clouddeck.net).
A workaround can help you narrow down the problem: if a user logs into Facebook to share the link with the [f] icon at the top (so without using the SoundCloud Facebook connection), then the SoundCloud Facebook connection will Work. I use the URL https://www.facebook.com/dialog/oauth for this function .
Screenshot above where SoundCloud Facebook connects to redirects 
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