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 ('9e5d12dbe2ca49dcae1b22b2f454d6c7', -1, 1711711701, 1711711701, '2cdec4ec', -10, 0, 0)

Line : 187
File : sessions.php