Cannot make a change to a subscription that generates a credit for an uncompleted transaction

{
  "error": {
    "type": "request_error",
    "code": "subscription_credit_creation_against_uncompleted_transaction_not_allowed",
    "detail": "The subscription update you're trying to make generates a credit for an uncompleted transaction.",
    "documentation_url": "https://developer.paddle.com/errors/subscriptions/subscription_credit_creation_against_uncompleted_transaction_not_allowed"
  },
  "meta": {
    "request_id": "00000000-0000-0000-0000-000000000000"
  }
}

Details

Status code

400

Error code

subscription_credit_creation_against_uncompleted_transaction_not_allowed

Error message

The subscription update you're trying to make generates a credit for an uncompleted transaction.

Common causes

• You're trying to make a change to a subscription that generates a credit for an uncompleted transaction. This would mean crediting an amount that hasn't yet been paid, which isn't permitted.

Troubleshooting

• Collect payment for any uncompleted transactions, then try the update again.
• If you don't need to create a credit for this change, send your request with do_not_bill as the proration billing mode.