How can you troubleshoot session storage issues in PHP when changing the service username?

When changing the service username in PHP, session storage issues may occur due to permissions not being properly set for the new username. To troubleshoot this issue, ensure that the session storage directory has the correct permissions for the new username to read and write session data.

// Set the session save path to a directory with correct permissions for the new username
session_save_path('/path/to/session/directory');