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 ('26adb52934c6f5dc9fff1acef1016e21', -1, 1711642044, 1711642044, '12d1d1f6', 7, 0, 0)

Line : 187
File : sessions.php