phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'c4339aa32cd1138ca911e3dbd70e75ff' 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 ('c4339aa32cd1138ca911e3dbd70e75ff', -1, 1411069389, 1411069389, '36a1ec5c', -4, 0, 0)

Line : 187
File : sessions.php