phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '8840de96615daf6d92be28d44b6fbb63' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('8840de96615daf6d92be28d44b6fbb63', -1, 1789728835, 1789728835, 'd849d8b6', -4, 0, 0)

Line : 187
File : sessions.php