phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO start_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in) VALUES ('497c8a480bcb4d76f53b2b21b4f7eb39', -1, 1414764129, 1414764129, '365252c9', -1, 0)

Line : 158
File : sessions.php