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 ('3a8420a1b1438c8dfc0eb66585f2bb02', -1, 1552955537, 1552955537, '365acce9', -4, 0, 0)

Line : 187
File : sessions.php