Within the last 12 months two users of my app received this German message "Erneute Gewährung fehlgeschlagen. Kaufe erst das Softwareprogramm" when they tried to "Restore" their subscriptions. I think the English mesage is "Regrant Failed! Please Purchase Software Application First".
It happened under iOS 10 and 11.
I already asked the Apple Support and iTunesConnect but nowone was able or willing to help me to explain what this messages cause or what the user need to do to resolve it.
Every input from you to get this resolved is highly appreciated!