PrestaShop White Screen — Fix It Step by Step [2026]

A white screen in PrestaShop (blank page, WSoD) is the most common symptom of a store failure: the browser shows an empty page with no content and no error. The cause is almost always in the logs — a white screen means PHP error display is disabled. Below is the full repair procedure: from a safe backup, through debug mode, to isolating the guilty module. An ad-hoc fix by a specialist costs 200–600 PLN net, and diagnostics with a report 500–1,500 PLN net.

Key takeaway: You fix a PrestaShop white screen in 6 steps: 1) back up files and database, 2) enable debug mode on a copy (_PS_MODE_DEV_), 3) read the error from the screen or PHP logs (error_log, var/logs/), 4) check the most common causes (PHP memory, file permissions, corrupted cache), 5) isolate the module — disable them one by one or via the ps_module table, 6) after the fix, test the full purchase path. Never fix production without a backup.

• ## Step 1: Backup — before you touch anything

A white screen does not destroy data, but a hasty "fix" will. Before changing anything

• back up the store files (the whole directory, not just var/),
• dump the database (mysqldump or your hosting tool),
• note the PrestaShop and PHP versions — you will need them for the diagnosis.

On hosting without SSH access, create the backup via the control panel (files + database) or ask hosting support. A backup takes 10 minutes; restoring a store without one takes hours or days.

• ## Step 2: Enable debug mode

The white screen appears because PHP error display is off. Enable debugging on a copy of the store

• in PrestaShop 1.7/8/9 edit config/defines.inc.php: set define('_PS_MODE_DEV_', true);,
• if you have no file access, ask your host to enable display_errors for the copy,
• refresh the page that showed the white screen.

Instead of a blank page you will see the full error message: file, line, class and message. That is 90% of the diagnosis. Full instructions: PrestaShop debug mode.

Warning: Enable debug mode only on a store copy. On production, error messages visible to customers leak server information and invite attackers.

• ## Step 3: Read the logs

If you cannot enable debug mode, go to the logs

• var/logs/ in the PrestaShop directory (daily files, e.g. dev.log, prod.log),
• PHP logs on your hosting — usually error_log in the store directory or ~/logs/,
• nginx/apache server logs — available in the hosting panel.

Look for entries from the last few minutes: PHP Fatal error, Allowed memory size exhausted, Cannot redeclare, Class not found. Where exactly to find logs and how to read them: PrestaShop logs.

• ## Step 4: Check the most common causes

Typical causes of a white screen, in order of probability

PHP memory exhausted

After adding a module or during a large import the store may exceed memory_limit. Raise the limit in .user.ini or the hosting panel (PrestaShop 8/9 runs comfortably from 256M), clear the cache and check whether the problem returns.

File permissions

After a hosting migration files often lose their permissions. The PrestaShop standard

• - directories: 755,

• - files: 644,

• the var/ directory and subdirectories: 775 (must be writable by PHP).

• Fix via SSH: find . -type d -exec chmod 755 {} \; and find . -type f -exec chmod 644 {} \;, then var/ separately.

Corrupted cache

Clear the cache via the panel (Advanced Parameters → Performance → Clear cache) or by deleting the contents of var/cache while keeping the directory structure. Also remove var/cache/dev and var/cache/prod.

• ## Step 5: Isolate the guilty module

If the logs point to a module (or there are no logs), disable modules one by one

1. panel → Modules → Module Manager, disable one at a time and refresh the page,
2. when the panel is blank too, disable via the database: UPDATE ps_module SET active = 0 WHERE name = 'module_name';,
3. once the store is back, re-enable modules one by one — the last one enabled before the error returns is the culprit.

Instead of guessing you can disable all modules except the essential ones in bulk, then re-enable in batches. Full procedure: PrestaShop module conflicts.

• ## Step 6: Fix, test, disable debug

Once you find the cause

1. fix the problem (update the module, correct permissions, raise the limit),
2. disable debug mode (_PS_MODE_DEV_ back to false) and clear the cache,
3. test the full purchase path: home → category → product → cart → checkout → order confirmation and email,
4. check the admin panel — a white screen can affect only the front end or only the admin.

When only the admin panel is blank

A blank admin panel with a working store is usually

• an exhausted memory_limit (the PrestaShop panel uses more memory than the front end),
• stale cache after an update — clear var/cache,
• an admin module conflict — disable the last installed module via the database.

After raising the memory limit to 512M for the diagnosis the panel comes back in most cases.

When to get help

The diagnosis itself (logs, debug, module isolation) is within reach of anyone comfortable with a console. A specialist is worth it when:

• the logs show no cause or point to the PrestaShop core,
• the white screen returns after every repair attempt,
• the store has been down for more than an hour — every hour means lost orders,
• the database is involved (corrupted tables, SQL errors).

An ad-hoc fix costs 200–600 PLN net, diagnostics with a report 500–1,500 PLN net. Report issues via the contact form, and ongoing technical help packages are available as a service: PrestaShop technical help.

Frequently asked questions

White screen in PrestaShop — where do I start?

Start with a backup, then enable debug mode on a store copy (_PS_MODE_DEV_ in config/defines.inc.php) and read the error. In 80% of cases the message points directly to the cause: memory limit, module error, file permissions or corrupted cache.

Does a white screen mean data loss?

No — a blank screen only means PHP error display is off; the database data remains untouched. The real risk is a hasty "fix" without a backup. That is why the first step is always a files and database backup.

The white screen appeared after an update — what to do?

Check var/logs/ and disable the most recently updated module. If the error appeared after a core update, follow the procedure in post-update problems — it covers rollback and testing.

How long does a white screen fix take?

In a typical case (memory limit, permissions, a single module) it is 1–3 hours of specialist work. Complex cases — a core conflict, corrupted database, infected files — can take 1–2 days. That is why the diagnosis starts with the fastest checks.

Sources and tools

• PrestaShop DevDocs — troubleshooting
• PrestaShop — support documentation
• PHP — memory_limit configuration
• OWASP — web application security

👉 White screen and the store is down? Describe the problem and hand over access via a secure channel — contact form or kontakt@informatix.com.pl. See also the full failure overview: PrestaShop help.

📖 See also: PrestaShop 500 error, debug mode and PrestaShop logs.