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 ('8077fde9e3d117c0372b892dd5c66d2d', -1, 1711616881, 1711616881, '0357d1a2', -11, 0, 0)

Line : 187
File : sessions.php