phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('70d62cb51801a1187b479d7cc0e5eacd', -1, 1411453031, 1411453031, '365245be', 32, 0)

Line : 315
File : sessions.php