phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('58f09c3f8c76c11456dcf58edaa83594', -1, 1529761882, 1529761882, '36e0ebb7', 3, 0, 0)

Line : 187
File : sessions.php