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 ('d2d1101466ea1d961df4c05e84ee3715', -1, 1711617843, 1711617843, '36e123e0', -6, 0, 0)

Line : 187
File : sessions.php