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 ('3ffc466b5f6ad43661e21b0700433b07', -1, 1711666970, 1711666970, '12eaa56b', 4, 0, 0)

Line : 187
File : sessions.php