PrestaShop down: 500 error, blank page, back office won't open

PrestaShop down with a 500 error, a blank page or a back office that won't open: until it's back, orders are stuck. We find the cause and put the store back online at a fixed price of €89, with a report explaining what happened and how to avoid it next time.

The most common causes

A PrestaShop store that suddenly stops almost always has a precise cause, usually one of these:

• a module just installed or updated that isn't compatible with your PrestaShop or PHP version;
• leftover overrides in the override folder after a module was uninstalled, replacing core classes that have since changed;
• stale cache: after an update or a file move, var/cache points to classes and templates that no longer exist;
• PHP changed by the host: an automatic switch to a new version breaks an old store, or an old one blocks an updated store;
• database: damaged tables, full disk, connection limits reached at peak traffic;
• file permissions changed by a migration or a manual intervention.

What you can safely check yourself

Before calling us you can do two checks that break nothing: ask your host whether anything changed (PHP version, limits, server migration) and recall the last change made before the outage, such as a module installed or an update launched. If you have file access, the host's error log often already says which file and line caused the error. Avoid deleting folders at random or reinstalling modules until the cause is clear.

What we do

• Diagnosis from the logs: we enable debug mode in a controlled way and read the PHP and web server logs to find the component that fails.
• Fixing the cause: we disable or fix the module, clean overrides and cache, realign the PHP version or permissions.
• Store check: home, categories, product page, cart and checkout, plus back office access.
• Quick malware check: if the outage is a symptom of an infection we stop and move to PrestaShop malware removal.
• Report: what broke, what we changed and how to avoid repeating the mistake.

Price and terms

The job has a fixed price of €89 and covers diagnosis and fix of one cause on one store, during office hours: Monday-Friday, 09:00-18:00. All prices are on the PrestaShop pricing page.

If the cause needs development - for example a custom module to fix - or work on the server, we stop and give you a quote before going ahead, hourly (€75/hour) or with hour packages. Out of hours, band rates apply, and response is guaranteed only with an active on-call plan.

A typical case

A clothing store goes blank on Monday morning. On Friday a shipping module had been updated. The logs show an error in a cart override left behind by an old discount module, uninstalled months earlier: the new shipping module called a method the override no longer had. With the orphan override removed and the cache rebuilt, the store is back online in under an hour; the report also lists the two other leftover overrides, to remove at leisure.

After the fix

If the outage came from an update run straight in production, next time it's better done on a copy: that's how we work in the upgrade to PrestaShop 9. To look after the store over time there is PrestaShop support with monthly maintenance, and for a full snapshot of the store's condition there's the check-up at €240.