What this procedure is
This article explains how to fix errors after switching themes in PrestaShop using the Back Office.
Applies to: PrestaShop 8.x.
Why you would do this
- Apply the correct configuration from the start.
- Avoid common checkout/SEO/email issues.
- Prepare the store for production.
Prerequisites
- Back Office access.
- A recent backup (recommended).
- If the change impacts payments/shipping, enable maintenance mode first (recommended).
Quick diagnosis (before you change anything)
1) Confirm you are on PrestaShop 8.x
Expected result: the menus match the paths shown here.
2) Record current settings
Expected result: you can revert if something goes wrong (notes/screenshots).
Steps — How to Fix Errors After Switching Themes
Step 1) Open the correct Back Office section
Path: Performance + Modules + Theme
Expected result: you see the related settings screen.
Step 2) Apply the main configuration
Review and adjust these points:
- Clear cache.
- Disable CCC temporarily.
- Disable theme modules one by one.
- Revert to previous theme if needed.
Expected result: settings are saved successfully.
Step 3) Save changes
Save and wait for confirmation.
Expected result: you see a success message.
Step 4) Clear cache and test
If you don’t see changes, clear cache and test in a private window.
Expected result: changes become visible.
Final verification
- Settings persist after reload.
- Storefront works normally.
- No new Back Office errors appear.
If something doesn’t work (common issues)
Changes are not visible
- Clear PrestaShop cache.
- If you use a CDN/proxy, purge cache there too.
- Test in an incognito/private window.
Checkout breaks after the change
- Revert the last change if you can identify it.
- Enable debug mode to see the real error.
- Restore your backup if needed.
Best practices
- Change one thing at a time and verify.
- Document: date, what changed, and why.
- Avoid changing payments/shipping during peak hours.