phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a56d76f5b770ede07b6ec412c8b6717c' 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 ('a56d76f5b770ede07b6ec412c8b6717c', -1, 1416846305, 1416846305, '36e21539', 66, 0, 0)

Line : 187
File : sessions.php