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, session_admin) VALUES ('e7b64f70c4c89091acd9c5d96cbe07a7', -1, 1490441931, 1490441931, '3691d0a0', -9, 0, 0)

Line : 187
File : sessions.php