Fix WooCommerce Checkout JSON Error

Job ID: 40426328

Budget: $100 – $125 USD

My WooCommerce-based e-commerce site throws a JSON “string/long” error the moment a customer clicks the Payment button in checkout. Everything up to that point—cart review, billing and shipping details—works normally; the failure happens precisely at payment processing, preventing any order from completing.

I need a developer who knows WooCommerce internals, WordPress hooks, and REST API responses to:

• trace the exact request/response that triggers the malformed JSON
• identify whether the issue comes from theme overrides, a plugin conflict, or a custom snippet handling long strings
• patch the root cause and verify the fix across major browsers and mobile

Deliverable: a clean, production-ready checkout flow with no JSON errors, plus a brief summary of what was changed so I can maintain it going forward.
Related categories: PHP JavaScript WordPress CSS HTML WooCommerce Web Development REST API