generic_decline
Generic decline. The card was declined for an unknown reason. Stripe's own Radar rules can also produce this code.
Will retrying the charge work?
Sometimes. Retry a couple of times over several days, but email the customer in parallel.
What to do about it
Retry later and email the customer. If you see a spike, check whether a Radar rule is blocking legitimate renewals.
What to tell your customer
The payment was declined. Try again or update your card.