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 ('d2d615b890a21719888f01c062dc2f15', -1, 1711708415, 1711708415, '03efcebf', 0, 0, 0)

Line : 187
File : sessions.php