I just tried to convert from PDF to Word in the iPad app and was told that I needed to subscribe. Assuming my subscription had lapsed, I resubscribed and I received an error (SKErrorDomain0).
I tried restoring purchases, only to receive another error (purchase could not be validated com.adobe.reader.inapp.ais.error99).
I tried subscribing again and it said I was already subscribed. I checked my subscription status in iTunes and Adobe Export PDF was listed as a new sub.
I repeated the above with no change. I tried subscribing again and this time it appeared to go through the new subscription process (for the second time today). The app still didn't detect my subscription, still produced the same error and still wouldn't restore purchases.
It's possible that I've just subscribed twice but still can't convert.