Common PHP Errors and How to Fix Them
Browse all documented PHP errors with detailed explanations, root causes, and step-by-step fixes.
Undefined variable: product in /var/www/html/cart.php on line 27
This error occurs when a variable is used before it is declared or assigned a value.…
Warning: Cannot redeclare class Foo in /var/www/html/autoloader.php on line 55
This error occurs when a PHP script attempts to declare a class with the same name in a different scope, usually due to …
Trying to access array offset on value of type null in /var/www/html/data.php on
This error occurs when a developer tries to access an element of an array or object using a key or property, but the val…
Undefined property: stdClass::$username in /var/www/html/login.php on line 42
This error occurs when you try to access a property of an object that doesn't exist. In PHP, this can happen when you're…
Undefined method 'render' for object of class 'stdClass' in /var/www/html/applic
This error occurs when the controller or method does not exist in the application or when the method is not properly imp…
Unexpected '}' at end of file in /var/www/html/script.php on line 1
This error occurs when the PHP interpreter encounters unexpected syntax at the end of a file. In this case, it's a closi…
Warning: fclose() expects parameter 1 to be resource, boolean given in /var/www/
This error occurs when a function that expects a resource (such as a file or database connection) is called with a boole…
PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate en
This error occurs when you attempt to insert a duplicate value into a column that has a unique constraint, such as a pri…
Fatal error: Uncaught Error: Cannot pass string to argument 1 of fgets(), expect
This error occurs when a PHP function that expects a resource (like a file pointer) is passed a string instead.…
Serialization of 'Closure' is not allowed in /var/www/html/api.php on line 67
This error occurs when you're trying to serialize or un-serialize a Closure (an anonymous function) in PHP, which is not…
SQLSTATE[HY000] [1040] Too many connections
This error occurs when the maximum number of allowed database connections has been exceeded, preventing new connections …
Call to undefined method Laravel\Support\Str::slug()
This error occurs when you're trying to use a method or function that doesn't exist in a specific class or object, in th…
Have a PHP error that's not listed? Get an instant explanation.
Explain Another Error