phpBB : Critical Error

Error creating new session

DEBUG MODE

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

INSERT INTO docttorrdiscluc_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('0c256f0d6ef27e0ec3cd07b519a2ec19', -1, 1544632434, 1544632434, '36e2243c', -4, 0, 0)

Line : 190
File : sessions.php