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 ('762afabf5b4eac483d23c8b66bec13b1', -1, 1534873895, 1534873895, '36c42a08', 5, 0, 0)

Line : 187
File : sessions.php