phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '18bb35325ec0cb7a6f6e9744fb84cd29' 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 ('18bb35325ec0cb7a6f6e9744fb84cd29', -1, 1406035520, 1406035520, '36ea52d8', 4, 0, 0)

Line : 187
File : sessions.php