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 ('ab4f6aef41171ccad7e76c793f6f2e5c', -1, 1711712735, 1711712735, '2ccc7539', -2, 0, 0)

Line : 187
File : sessions.php