I use anjlab library for in-app subscription purchasing. Recently some users started reporting that they are unable to purchase subscription. If they click on purchase button Play Store purchase dialog won't popup at all - I can't replicate this with production nor testing subscription. From provided logs I can see there is billing error with code 101 (BILLING_ERROR_FAILED_TO_INITIALIZE_PURCHASE) but without any further details. Users confirmed they have latest Play Store app and valid payment method. Also they are able to initialize purchase from another app.
Do anybody know what's the reason for 101 error and how to resolve it?