WooCommerce Support – Fix Checkout Error, Cart Issues, Payment Gateway

Checkout page spinning forever? Payment failed for some cards only? I debug WooCommerce core, third-party gateways and shipping rules, then patch or roll back—without losing live orders.

Critical WooCommerce Errors I Fix

• "Sorry, there has been a critical error on this website" on /checkout
• Cart emptied after login or language switch (WPML)
• PayPal/Stripe webhook returns 404 or 500
• Variable product price shows 0,00 € until page refresh
• Shipping zone not matching for some postcodes
• Coupon applies twice when guest converts to account
• Stock reduced twice on failed payment
• Order email not sent (background CRON stuck)

Payment Gateway Debugging

1. Stripe: logs on dashboard + server TLS 1.2 check
2. PayPal: IPN history vs WooCommerce note mismatch
3. Amazon Pay: keys region vs store base location
4. Scalapay: callback URL blocked by WAF
5. Bank transfer: order-on-hold → processing transition

Speed & Scalability Tweaks

• Move wp_postmeta for orders to custom table (CPT)
• Disable admin-ajax?wc-ajax=checkout when using REST
• Cache cart fragments only for guests (0 items)
• Index lookup on wp_wc_order_product_lookup
• Separate object cache group for sessions on Redis
• Lazy-load product gallery on mobile

Security & Compliance

• Force SSL on /my-account and /checkout via 301
• Rate-limit login and coupon apply endpoints
• Sanitize uploaded invoice attachments (PDF)
• Separate database user with SELECT only for reporting
• Mask order key in email subject to prevent enumeration

ERP / CRM Integration

I build secure bridges that sync:

• Products, stock, prices (two-way)
• Customers and billing address
• Orders and invoice PDF
• Tracking numbers back to WooCommerce

Supported: SAP Business One, Danea EasyFatt, Zucchetti AdHoc, Holded, Xero, QuickBooks.

Pre-Support Checklist

• Active payment gateway and last successful transaction ID
• Exact error text or screenshot (both frontend and log)
• PHP error log and WooCommerce > Status > Logs
• Hosting panel or SSH access for live debugging
• Staging copy where I can safely enable SCRIPT_DEBUG

Quick FAQ

Will customers lose cart contents during fix?

No. I work on staging or use maintenance mode with cart session persistence.

Do you support multi-currency?

Yes. I configure Aelia or WPML multi-currency and test exchange-rate cache.

Can you speed up a 30-second checkout?

Usually down to 2–3 s by profiling with Query Monitor and removing unused shipping zones.

Need Store Rescue?

Send me the last failed order number and gateway log. I’ll quote a flat fee and start immediately.