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 ('cb50cf7edeffad94d58bb962d3aad863', -1, 1728521068, 1728521068, '2cc05fa1', 0, 0, 0)

Line : 172
File : sessions.php