Google Play In-App Purchase returns error code -1008: null puchaseData or dataSignature

I had this problem myself. After a while I found what I did wrong. I was calling the wrong method on the IABHelper.

If you call mHelper.launchPurchaseFlow(...) with an SKU that is registered as a subscription on Google Developer Console it will result in the error: IAB returned null purchaseData or dataSignature (response -1008:Unknown error).

If you have a SKU that is registered as an subscription you have to use the method: mHelper.launchSubscriptionPurchaseFlow(...) instead.

Hope this helps.