Hello!
An error in processing a subscription can occur for several reasons, including issues with the payment system, incorrect API settings, or issues with user cards. It is recommended to check that your payment gateway settings are configured correctly and that your customers are using current and supported payment methods.
If you want to avoid such errors in the future and make the payment process more stable, I recommend considering
https://paymentgateway.me/. This service supports a flexible payment system and is suitable for different types of businesses, ensuring easy integration and minimizing disruptions in processing subscriptions.
Good luck in solving the problem!