[Closed] Google IAP DuplicateTransaction and failed purchase issue.

I have an IAP set up as a non-consumable, the implementation has worked fine for hundreds of players. A few (3?) of them have reported issues with it however.

For these few google says the purchase has gone through, they get an email from google saying they've been billed but they don't get anything rewards in-app.

On reopening the app they see this non-consumable item as still available for purchase. Attempting to re-purchase it triggers OnPurchaseFailed() with the reason as "DuplicateTransation".

So, two issues - 1. How can I work out why is this failing in the first place and 2. is there any way to recover from this error happening?

Currently the issues appear to leave players charged for something they want that they haven't received and without the ability even to pay again.

 

They may have an unfinished transaction in the cache. Have them clear the Google Play cache https://spryfox.zendesk.com/hc/en-u...How-do-I-clear-my-Google-Play-Services-cache-