Session Already Started

Why This Happens

This warning occurs when session_start() is called multiple times in the same request. This commonly happens when session_start() is in a header file that gets included multiple times, or when a framework starts the session automatically and you call it again manually.

The Problem

session_start();
// ... later in included file ...
session_start(); // Session already active

The Fix

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

Step-by-Step Fix

1. 1

   Find all session_start calls

   Search your codebase for all occurrences of session_start() to find where it is called more than once.

2. 2

   Use a session status check

   Wrap session_start() in a session_status() check to only start a session when one is not already active.

3. 3

   Centralize session management

   Start the session in one place, such as a bootstrap file or middleware, and remove all other session_start() calls.