phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '-1' for key 2

INSERT INTO elranchito_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('9fad9ccc4eee88cdc80a4f5a26d228c1', -1, 1472073851, 1472073851, '3650f79e', 2, 0, 0)

Line : 172
File : sessions.php