phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1bb2fc4736e984407527eb873c025356' for key 1

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('1bb2fc4736e984407527eb873c025356', -1, 1371533507, 1371533507, '36f2adb9', -9, 0, 0)

Line : 187
File : sessions.php