Error: Failed to start application: Failed to start the session

Question

I have hosted web application develop using joomla in ubuntu 20 and use mysql as database. one i hosted and viewed in the web browser it show me Error: Failed to start application: Failed to start the session

i have used php 7.4, mysql Ver 8.0.27, apache Apache/2.4.41 (Ubuntu)

Answer 1

Joomla works with sessions. It needs to be able to write session info to the #__session table in the database. Your error message indicates that Joomla cannot write to the database, hence it cannot start its session.

Could you double check your MySQL credentials with the credentials in your configuration.php?

 public $dbtype = 'mysqli';
 public $host = 'localhost';
 public $user = 'some-user';
 public $password = 'some-secret-password';
 public $db = 'the-name-of-your-database';
 public $dbprefix = 'the-table-prefix_';

Answer 2

1. Common causes for the “failed to start session” error in Joomla: see https://forum.joomla.org/viewtopic.php?t=982009

2. Make sure that your version of PHP can connect to the database: see Optional Technical Requirements for J! 3.x

3. Unusual causes for this error: (a) Tinkering with the file configuration.php to change the SQL user password; or (b) Is your disk full?