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 ('c6612e1d9a0ce164f4117cc708311541', -1, 1542128628, 1542128628, '36eb306a', 76, 0, 0)

Line : 187
File : sessions.php