I have an application published on the Google Play Store with an in-app purchase to upgrade to the full version. The IAB library has been updated to version V3 in the latest version of the application.
Many users complain that they cannot buy the update. Error: "Authentication required. You need to log in to your Google account."
I also noticed this error in the logs: BasicNetwork.performRequest: Unexpected 403 response code for https://android.clients.google.com/fdfe/preparePurchase
This is a managed product. I checked SKU, keys, everything, but could not find the cause of this error. My users are complaining and I'm losing revenue ... Any help would be greatly appreciated!