Shopify and Checkout Issues
Shopify handles hosting, security, and infrastructure — so when something breaks, the problem is usually in your theme, apps, or configuration. The good news: you don't need server access to fix most issues. The bad news: Shopify's managed environment means fewer diagnostic tools than self-hosted platforms.
This guide covers the most common Shopify problems and how to fix them. For platform-agnostic form issues, see Form Failures. For the broader troubleshooting framework, see Fixes & Troubleshooting.
Checkout problems
Checkout breaks cost sales immediately. Every failed checkout is a lost conversion — and unlike abandoned carts, the customer wanted to buy.
Payment declined issues
Customer enters payment, clicks submit, gets declined.
| Symptom | Likely cause | Fix |
|---|---|---|
| All payments declined | Payment provider misconfiguration | Check Shopify Payments settings, verify API keys |
| Specific card types fail | Card type not enabled | Enable the card type in payment settings |
| International payments fail | Currency or region restriction | Check payment provider regional settings |
| "Error processing payment" | Gateway timeout | Check payment provider status page |
Diagnosis: Shopify Admin → Settings → Payments. Verify your payment provider is active and properly configured. Test with Shopify's bogus gateway in test mode. Check your payment provider's dashboard for declined transaction details.
Checkout not loading
Customer clicks checkout, sees infinite spinner or error.
Common causes:
- JavaScript errors from apps
- Theme liquid errors in checkout customizations
- Browser extension conflicts
- Third-party scripts blocking checkout
Diagnosis:
- Open browser DevTools → Console
- Look for JavaScript errors
- Try in incognito mode (no extensions)
- Disable apps one by one
Fix: If the problem disappears in incognito or with apps disabled, you've found your culprit. Remove or reconfigure the problematic app.
Missing checkout fields
Required fields don't appear, or custom fields disappear after theme update.
Causes:
- Theme customization overwritten by update
- Checkout.liquid modifications lost
- App-injected fields not loading
Fix: Check if you have a custom checkout.liquid file. If you're on Shopify Plus, verify checkout customizations are still in place. For apps that add fields, check the app is still active and configured.
App conflicts
Shopify apps are powerful but they can interfere with each other and with your theme.
Identifying app conflicts
Symptoms:
- Features work sometimes, not always
- Errors appear after installing new app
- Checkout breaks after app update
- JavaScript errors mentioning specific app names
Diagnosis process:
- Note when the problem started
- Identify apps installed or updated around that time
- Disable suspect apps (Apps → App name → Disable)
- Test if problem persists
- Re-enable apps one at a time, testing after each
Prevention: Before installing any app, check reviews for mentions of conflicts. Test new apps on a development store first if possible.
Common conflict patterns
| Conflict type | Symptoms | Resolution |
|---|---|---|
| Multiple cart apps | Cart behavior inconsistent | Choose one cart management app |
| Overlapping functionality | Features interfere | Disable duplicate features in one app |
| Script injection order | Elements don't appear | Contact app developers about load order |
| API rate limiting | Slow store, timeout errors | Reduce apps making API calls |
Theme issues
Themes control your store's appearance and much of its functionality. Problems here affect everything customers see.
Changes not appearing
You made changes in the theme editor, but the live store looks the same.
Causes:
- Browser cache
- CDN cache
- Theme not published
- Changes made to wrong theme
Fix:
- Hard refresh (Ctrl+Shift+R or Cmd+Shift+R)
- Check you're editing the published theme
- Wait 2-3 minutes for CDN propagation
- Try incognito window
Theme breaks after update
Theme update overwrites your customizations.
Prevention:
- Duplicate your theme before updating
- Document all customizations (file names, changes made)
- Use a child theme approach when possible
- Keep CSS/JS customizations in separate files
Recovery:
- Shopify saves previous theme versions
- Go to Themes → Actions → Duplicate to save current state
- Go to Themes → Actions → Download theme file
- Compare with your documented customizations
Slow theme performance
Store feels sluggish, pages load slowly.
Common causes:
- Unoptimized images
- Too many apps injecting scripts
- Heavy Liquid code
- Large CSS/JS files
Diagnosis: Check Core Web Vitals with PageSpeed Insights. Look at Network tab for large files.
Quick fixes:
- Compress images, use WebP format
- Lazy load below-fold images
- Audit app scripts (Settings → Apps → Data access)
- Remove unused apps entirely
Debugging Shopify-specific issues
Check Shopify status
Before debugging, check status.shopify.com. If Shopify is having issues, wait for them to resolve.
Use preview mode
Theme Editor → Preview gives you a non-cached version of your store. Use this to test changes before publishing.
Check order timeline
For checkout issues, look at the order timeline: Admin → Orders → [Order] → Timeline. This shows what happened during checkout.
Contact Shopify support
When to escalate:
- Payment processing issues you can't resolve
- Checkout completely broken
- Admin access problems
- Suspected security issues
Shopify support can see server-side logs you can't access.
Related pages
Parent: Fixes & Troubleshooting — Platform-specific solutions that actually work
Deep dives:
- Shopify Checkout Broken — When customers can't complete checkout
- Payment Gateway Errors — Diagnosing and fixing payment failures
Siblings:
- WordPress Fixes — Common WordPress problems and solutions
- Form Failures — Form problems across all platforms
Related:
- Error Monitoring — Catch JavaScript errors affecting checkout
- Conversion Tracking — Know when checkout problems affect revenue