phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '0' 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 ('6adee751401102a3b5d3f2dfa078f987', -1, 1552955370, 1552955370, '365acce9', -2, 0, 0)

Line : 187
File : sessions.php