Diagnose the 503 Overloaded error in PrestaShop

A 503 Overloaded error doesn't prove a geolocation block on its own. Note down the URL, the affected IP, the time and the exact body of the response; also check whether the 503 comes from PrestaShop, the web server or a proxy.

The version is decisive:

• PrestaShop 1.6 could respond with a 503 when showing its restricted country template. Tell restricted-country.tpl apart from the maintenance page before changing settings.
• PrestaShop 1.7 and later respond with a 403 to a geographic restriction; a 503 from the core is associated with maintenance. Also review the server logs to rule out infrastructure limits or errors.

If you have confirmed a geographic restriction, review Preferences > Geolocation in PrestaShop 1.6 or International > Localization > Geolocation in later versions. GeoIP databases may misclassify mobile, corporate or VPN connections. Since PrestaShop 8.1, new installations no longer include by default a search engine whitelist that goes out of date.

Turn off or change the restriction only after verifying it, and repeat the same request from an affected IP. If the code is still 503, restore the setting and continue diagnosing from the logs: geolocation wasn't the cause.

Check that the fix doesn't change the expected access

The responses described are those of the core in those versions; a module, an override or a proxy may change them. Save the previous settings and change only one option so you can compare the same URL and connection.

After fixing a wrong restriction, check the catalogue, cart and checkout start from the affected connection and confirm that access for the other countries stays as intended. If your shop is still on PrestaShop 1.6, keep this diagnosis for that installation and plan its upgrade on a test copy.