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 ('e8721df49ddc8b0eb6cb2092a74a804f', -1, 1490228089, 1490228089, '369eb7bc', 12, 0, 0)

Line : 187
File : sessions.php