How to Fix Common Laravel Application Errors (500, CSRF, Queue Deadlocks)

Diagnosing and Resolving Production Laravel Errors

Encountering production errors can halt your business operations. Here is how our engineering team systematically diagnoses and resolves the most frequent Laravel issues:

1. 500 Internal Server Errors

Never rely on generic error pages. Inspect storage/logs/laravel.log or use error telemetry tools like Sentry. Common root causes include misconfigured .env database credentials, missing PHP extensions (such as ext-bcmath or ext-intl), and storage directory permissions issues on Linux servers (ensure storage/ and bootstrap/cache/ are writable by www-data).

2. 419 Page Expired (CSRF Token Mismatch)

This error occurs when the session token expires or is missing from an HTTP POST request. Ensure your Blade form includes the @csrf directive. If making AJAX requests via Axios or fetch, ensure the X-CSRF-TOKEN header is extracted from the meta tag: meta[name="csrf-token"].

3. Database Deadlocks in Background Queues

When multiple queue workers update the same table simultaneously, InnoDB deadlocks can occur. Resolve this by wrapping transactions in DB::transaction() with automatic retries (e.g. DB::transaction(callback, 5)) and sorting batch updates by primary key.