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 ('8d1f51f5e18d2306968a340a2349f3d2', -1, 1714001977, 1714001977, '12e03f57', -7, 0, 0)

Line : 187
File : sessions.php