| Undefined array key |
Warning: Undefined array key / Undefined index |
Your code reads an array key that doesn’t exist — common with `$_GET`, `$_POST` and decoded JSON. |
| Implicit float to int |
Deprecated: Implicit conversion from float 2.5 to int loses precision |
PHP 8.1+ warns when a float with a fractional part is silently converted to int (array keys, % operator, int… |
| Call to undefined function |
PHP Fatal error: Uncaught Error: Call to undefined function |
PHP can’t find the function you called — usually a missing extension, missing include, or namespace issue. |
| Parse error |
PHP Parse error: syntax error, unexpected … |
PHP can’t parse the file because of a syntax mistake — the real error is often on the line before the one rep… |
| mysqli_sql_exception |
Fatal error: Uncaught mysqli_sql_exception |
A MySQLi query or connection failed; since PHP 8.1 MySQLi throws exceptions by default. |
| Cannot redeclare |
Fatal error: Cannot redeclare function foo() (previously declared in …) |
The same function (or class) was defined twice — usually a file included more than once. |
| cURL error 28 |
cURL error 28: Operation timed out after 30001 milliseconds with 0 bytes received |
A PHP cURL (or Guzzle) request timed out before the remote server answered. |
| TypeError |
Fatal error: Uncaught TypeError: foo(): Argument #1 ($x) must be of type int, string given |
A function received a value of the wrong type for a typed parameter. |
| could not find driver |
PDOException: could not find driver |
The PDO driver for your database (pdo_mysql, pdo_pgsql, pdo_sqlite) isn’t installed or enabled. |
| Array to string conversion |
Warning: Array to string conversion |
An array was used where a string is expected — echoing it, concatenating it, or passing it to a string functi… |
| Undefined variable |
Warning: Undefined variable $x |
PHP read a variable that was never assigned in the current scope. |
| Call to member function on null |
Fatal error: Uncaught Error: Call to a member function x() on null |
Code called a method on a variable that is null instead of an object. |
| DivisionByZeroError |
Fatal error: Uncaught DivisionByZeroError: Division by zero |
Code divided by zero (or used modulo by zero) — PHP 8 throws instead of warning. |
| Unsupported operand types |
Fatal error: Uncaught TypeError: Unsupported operand types: string + int |
An arithmetic or array operator was used with incompatible types (PHP 8 is stricter than PHP 7). |
| cURL error 35 |
cURL error 35: OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to host:443 |
The TLS handshake failed — protocol/cipher mismatch, a proxy interfering, or the server closed the connection. |
| Primary script unknown |
FastCGI sent in stderr: "Primary script unknown" |
Nginx passed a script path to PHP-FPM that PHP-FPM couldn’t find — usually a wrong SCRIPT_FILENAME or root. |
| ArgumentCountError |
Fatal error: Uncaught ArgumentCountError: Too few arguments to function foo(), 1 passed and exactly 2 expected |
A function was called with fewer arguments than it requires. |
| Maximum execution time |
PHP Fatal error: Maximum execution time of 30 seconds exceeded |
The script ran longer than `max_execution_time` and PHP stopped it. |
| intl missing |
Class "NumberFormatter" not found / The "intl" PHP extension is required |
Code uses the intl extension (NumberFormatter, Collator, IntlDateFormatter) but it isn’t installed. |
| Uncaught Exception |
Fatal error: Uncaught Exception: message in file.php:12 |
An exception was thrown and nothing caught it, so PHP stopped the script. |
| failed to open stream |
Warning: include(x.php): Failed to open stream: No such file or directory |
PHP couldn’t open a file for include/require/fopen — wrong path, missing file, or no permission. |
| cURL error 6 |
cURL error 6: Could not resolve host: api.example.com |
PHP cURL couldn’t resolve the hostname via DNS. |
| Allowed memory size exhausted |
PHP Fatal error: Allowed memory size of X bytes exhausted |
The script tried to use more memory than PHP’s `memory_limit` allows. |
| BOM output |
Unexpected characters at the top of the page / headers already sent by BOM |
A UTF-8 byte-order mark (BOM) at the start of a PHP file is sent as output, breaking headers, JSON and images. |
| session save path |
Warning: session_start(): open(/var/lib/php/sessions/sess_x, O_RDWR) failed: Permission denied |
PHP can’t write session files to the configured session.save_path. |
| Deprecated null to internal |
Deprecated: strlen(): Passing null to parameter #1 ($string) of type string is deprecated |
PHP 8.1+ warns when null is passed to a built-in function that expects a string/int. |
| Maximum function nesting |
Fatal error: Maximum function nesting level of '256' reached, aborting! |
Recursion went deeper than Xdebug’s max_nesting_level allows (or PHP crashed with a segfault without Xdebug). |
| json_decode null |
json_decode() returns null / JSON_ERROR_SYNTAX: Syntax error |
The string passed to json_decode isn’t valid JSON, so PHP returns null. |
| PHP mail |
PHP mail() returns false / emails not delivered |
PHP’s mail() function failed or emails never arrive (spam or rejected). |
| Headers already sent |
Warning: Cannot modify header information - headers already sent |
You called `header()`, `setcookie()` or `session_start()` after output had already been sent to the browser. |
| Array offset on null |
Warning: Trying to access array offset on value of type null |
Code used `$x['key']` where `$x` is null — usually a lookup or function that returned nothing. |
| Composer memory |
Composer: PHP Fatal error: Allowed memory size of 1610612736 bytes exhausted |
Composer ran out of memory while resolving or installing dependencies. |
| 419 Page Expired |
Laravel: 419 Page Expired (CSRF token mismatch) |
Laravel rejected a POST because the CSRF token was missing, expired or didn’t match the session. |
| SQLSTATE[HY000] [2002] |
PDOException: SQLSTATE[HY000] [2002] Connection refused |
PHP couldn’t reach the database server at the host/port in your DSN. |
| OPcache stale code |
PHP still runs old code after deploy (OPcache not reset) |
OPcache keeps serving cached bytecode, so changes uploaded to the server don’t take effect. |
| session_start() |
Warning: session_start(): Session cannot be started after headers have already been sent |
session_start() ran after output was sent, so PHP can’t set the session cookie. |
| Cannot use object as array |
Fatal error: Uncaught Error: Cannot use object of type stdClass as array |
Code used array syntax (`$x['key']`) on an object. |
| No application encryption key |
Laravel: No application encryption key has been specified. |
Laravel’s APP_KEY is missing, so it can’t encrypt sessions and cookies. |
| Target class does not exist |
Laravel: Target class [App\Http\Controllers\X] does not exist. |
Laravel’s container couldn’t find the controller or class named in a route or binding. |
| Undefined property |
Warning: Undefined property: Class::$prop |
Code read an object property that doesn’t exist on that object. |
| max_input_vars |
Warning: Unknown: Input variables exceeded 1000. To increase the limit change max_input_vars in php.ini. |
The form submitted more fields than PHP’s max_input_vars allows; extra fields were silently dropped. |
| Composer conflict |
Your requirements could not be resolved to an installable set of packages. |
Composer can’t find package versions that satisfy every constraint (PHP version, extensions, other packages). |
| Dynamic property deprecated |
Deprecated: Creation of dynamic property Foo::$bar is deprecated |
PHP 8.2+ deprecates creating properties that aren’t declared in the class. |
| GD missing |
Fatal error: Uncaught Error: Call to undefined function imagecreatefromjpeg() |
The GD extension (or its JPEG/WebP support) isn’t installed for the PHP version serving the site. |
| Laravel table not found |
Laravel: SQLSTATE[42S02]: Base table or view not found: 1146 Table 'db.sessions' doesn't exist |
Laravel queried a table that hasn’t been created — usually sessions, cache, jobs or a new model’s table. |
| Laravel storage |
Laravel: The stream or file "storage/logs/laravel.log" could not be opened in append mode: Failed to open stream: Permission denied |
The web server can’t write to Laravel’s storage or bootstrap/cache directories. |
| UPLOAD_ERR_INI_SIZE |
PHP upload error 1: The uploaded file exceeds the upload_max_filesize directive in php.ini |
The uploaded file is bigger than PHP’s upload_max_filesize, so PHP discarded it. |
| Class not found |
PHP Fatal error: Uncaught Error: Class "X" not found |
PHP couldn’t load the class — autoloading failed, the namespace is wrong, or the dependency isn’t installed. |
| open_basedir |
Warning: file_exists(): open_basedir restriction in effect. File(/x) is not within the allowed path(s) |
PHP is configured to access only certain directories, and the script tried to touch a file outside them. |
| Vite manifest not found |
Laravel: Vite manifest not found at: public/build/manifest.json |
Laravel’s @vite directive can’t find the compiled asset manifest because assets weren’t built. |