I have added some credit test users to my app and try to make payment subscritpions. At the beginnings everything worked fine, but lately I'm getting some issues related to this. Further speaking, I'm getting the message: Sorry, there was a problem and we can’t complete your request. Please try again later. with consecuent client callback data setted to null. I suspect I didn't have made any significant change in FB.ui call for the subscription payment dialog. Could anybody share his/her thaughts about this?
I have seen into developers.facebook support pages and no much feedback is provided concerning to this.