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 ('51d1d8ccecfdf9da69da8e56d415acd5', -1, 1711700008, 1711700008, '3417e7cf', -4, 0, 0)

Line : 187
File : sessions.php