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 ('a6ab27d8a2b2f9d67bc9a34c4d4a5509', -1, 1711625666, 1711625666, '6b179d10', -1, 0, 0)

Line : 187
File : sessions.php