Module development, admin/system.xml configuration, plugins, observers, DI and backend how-tos for Magento 2 & Adobe Commerce.
28 articles
The Magento 2 "Unable to unserialize value. Error: Syntax error" almost always means an old PHP serialize() value is sitting where Magento now expects JSON, usually after an upgrade or a mismatched database restore. This guide fixes it fix-first for 2.4.4 to 2.4.9: flush the cache, read the stack trace to find the table, then convert or clear the one bad row safely.
Grey placeholders, broken thumbnails, or 404s under /media/catalog/product/cache/ have a short, fixable list of causes. This guide works through each one fix-first for Magento 2.4.4 to 2.4.9: regenerating the resized cache, the 660 permission trap after a migration, missing originals, base media URL, CDN cached 404s, and wrong store-view or image roles.
The Magento 2 "Area code not set" and "Area code is already set" errors both come from one rule about when an area must exist. This guide fixes them fix-first for Magento 2.4.4 to 2.4.9 in custom console commands, bootstrap scripts, setup patches, and indexers, with full runnable code.
Most Magento 2 email problems are not SMTP problems. Since 2.3, order and invoice emails are queued and only sent when cron runs, so a dead cron means silence. Here is the fix-first path: queue and cron, then SMTP, then SPF, DKIM, DMARC and templates.
Forgot the Magento 2 admin password or stuck at the two-factor prompt after a new phone? This guide fixes both from the command line for Magento 2.4.4 to 2.4.9: the supported password reset, a safe database route, account unlock, and the real 2FA gotcha (server clock drift).
Magento 2's "There has been an error processing your request" page hides the real exception behind a report ID. This guide shows you how to read var/report, surface the error safely, and fix the causes that trigger it most: stale DI, permissions, a throwing module, memory limits, and bad DB creds.
The Magento 2 "Could not validate a connection to Elasticsearch/OpenSearch" error has a short, fixable list of causes. This guide works through each one fix-first for Magento 2.4.4 to 2.4.9: the engine value, the Docker service hostname, port 9200, OOM on small boxes, TLS and auth, index prefixes, and the reindex that finishes the job.
Six ways to intercept Magento 2, one decision table. Real observer and plugin code, the grep that lists every event a module dispatches, and three production bugs caused by picking the wrong tool.
Most order grid tutorials break filtering, sorting, or CSV export the day you paste them. Here are the three ways I add order grid columns on real stores, including the one Magento itself uses.
InstallData is dead. This is the data patch pattern I ship to client stores: one class, dropdown options, attribute set assignment, and a patch_list war story from a live deploy.
