phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'd6acf8ce272cc1dc0e1b42a20ff9c646' for key 1

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('d6acf8ce272cc1dc0e1b42a20ff9c646', -1, 1529622886, 1529622886, '369e0f61', 0, 0, 0)

Line : 187
File : sessions.php