In-App Purchase fails to unlock content on some devices

Question

We have had users reporting that they have paid for our product via in-app purchase but we have failed to unlock the content. The common denominator between these reports is iOS 9 so far. It seems like the purchase with success method does not get called. The IAP seems to work and even says that the purchase has been restored successfully (Apple's own alert), yet it does not deliver the content (unlocks the app).

This is a very odd bug because it works perfectly fine on iOS 10, and there is no reason why it should't work on other older devices. At some point, we had a customer complain of the same issue with iOS 10 as well and we just can't produce the issue. I am using RMStore for my in app purchases but this has not started since we used this library. It has been happening even with standard IAP integration.

Does anyone knows or may have heard of what causes this issue?

Any tips would be great!

Answer 1

I have several apps on the App Store and I'm facing similar issues. For about 1% of the users, the success callback is not called after an in-app purchase. If the users restore their purchases later, the purchased features unlock properly, so the App Store processed the purchase properly, and this is likely a bug in the app. I could never find the issue as I could not reproduce it on any of my devices.

After I just read that you use RMStore, I checked the emails that my users sent me during the last two years about this issue and noticed that this occurs exclusively with apps that use RMStore. While the code of that library looks really clean, I assume that the bug is somewhere hidden in there.

As RMStore hasn't been updated since almost two years, I consider it deprecated and will remove it from my apps in the near future. I will update this answer if the issue persists after the removal.

Update after three months: After the removal of RMStore for the in-app purchase handling from one of my apps, the problems have apparently disappeared.