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 ('77dabc778d894cdb12dda5aa0f33f3d0', -1, 1709503712, 1709503712, '22cca9e6', 6, 0, 0)

Line : 187
File : sessions.php