PHP Error Library

Practical PHP error explanations with causes, diagnosis steps, and modern fixes.

Paste your PHP error

Paste a fatal, warning, SQLSTATE, or cURL message. Paths and line numbers are normalized and are not stored.

Open full Error Matcher

PHP errors are often more actionable than they look—if you know which fragment of the message matters. This library focuses on real diagnostic workflows: isolate the message, identify the subsystem, reproduce with the smallest input, then apply a fix that survives PHP upgrades.

Paste a full fatal/warning into the matcher, browse categories such as Composer, Xdebug, PHP-FPM, Apache, nginx, and database/SQLSTATE issues, or filter by PHP version and environment. Every guide starts near the answer—no generic “PHP is popular” filler.

Cross-link into the PHP Error Matcher, Configuration Inspector, and Composer Platform Checker when text analysis helps more than another prose page.

Browse by category

Syntax & Parse

8 guides

Parser and tokenization failures.

Variables & Constants

4 guides

Variable scope and constant lookup.

Arrays

7 guides

Array keys, offsets, and shapes.

Strings

2 guides

String operations and encoding.

Functions

7 guides

Function declarations and calls.

Classes & Objects

9 guides

Object model and property failures.

Namespaces & Autoload

4 guides

Name resolution and loading.

Type Errors

10 guides

Runtime type contract violations.

Exceptions

4 guides

Thrown and uncaught exceptions.

Warnings & Notices

9 guides

Non-fatal runtime diagnostics.

Deprecated

2 guides

Version migration deprecations.

Filesystem

3 guides

File paths, permissions, and streams.

Uploads

3 guides

HTTP upload handling.

Sessions & Cookies

7 guides

Session persistence and cookies.

Headers & Output

4 guides

HTTP output ordering.

JSON

4 guides

JSON parsing and encoding.

Date & Time

2 guides

Timezone and date processing.

Memory & Performance

4 guides

Resource and execution limits.

Composer

17 guides

Dependency and autoload tooling.

PDO

4 guides

PDO drivers and statements.

MySQL & MariaDB

10 guides

Database server errors.

Database Connections

4 guides

Connection and authentication.

cURL & HTTP

3 guides

Outbound HTTP transfers.

SSL Certificates

1 guides

TLS trust and certificates.

PHP Extensions

3 guides

Extension loading and availability.

PHP-FPM

8 guides

FastCGI process management.

Apache

4 guides

Apache PHP integration.

nginx

4 guides

nginx FastCGI integration.

Xdebug

9 guides

Xdebug diagnostics.

OPcache

3 guides

Bytecode cache configuration.

CLI

5 guides

Command-line PHP.

Cron

3 guides

Scheduled PHP tasks.

WordPress PHP

2 guides

WordPress runtime integration.

Laravel PHP

2 guides

Laravel container and runtime.

Symfony PHP

1 guides

Symfony services and runtime.

Zend & Laminas

2 guides

Zend Studio and Laminas runtime.

Legacy PHP

6 guides

Removed and historical behavior.

PHP Version Compatibility

3 guides

Cross-version migration failures.

php.ini

9 guides

PHP configuration directives.

Filter the library

162 matching guides

Title Pattern Severity
WordPress critical error There has been a critical error on this website. fatal
WordPress function undefined Fatal error: Uncaught Error: Call to undefined function wp_enqueue_script() in %s on line %d fatal
Xdebug already loaded Cannot load Xdebug - it was already loaded warning
Xdebug could not connect to debugging client Xdebug: [Step Debug] Could not connect to debugging client. Tried: %s:%d warning
Xdebug Docker client host unreachable Xdebug: [Step Debug] Could not connect to debugging client. Tried: localhost:%d warning
Xdebug invalid mode Xdebug: [Config] Invalid mode 'debugger' set for 'xdebug.mode' configuration setting warning
Xdebug legacy port 9000 mismatch Xdebug: [Step Debug] Could not connect to debugging client. Tried: %s:9000 warning
Xdebug log permission denied Xdebug: [Log Files] File '/var/log/xdebug.log' could not be opened. warning
Xdebug maximum function nesting level reached Fatal error: Maximum function nesting level of '256' reached, aborting! fatal
Xdebug profiler output could not be opened Xdebug: [Profiler] File '/tmp/cachegrind.out.123' could not be opened. warning
Xdebug trace file could not be opened Xdebug: [Tracing] File '/traces/trace.123.xt' could not be opened. warning
Zend Studio legacy Xdebug configuration Xdebug: [Config] The setting 'xdebug.remote_enable' has been renamed warning

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FAQ

How should I search for a PHP error?

Paste the distinctive message fragment or the full fatal/warning line. Dynamic paths and line numbers are normalized automatically.

Are these pages replacements for the PHP manual?

No. They are practical troubleshooting guides that complement php.net, Composer, Xdebug, and server documentation.