phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'f4777d54c41f49302148b9f2a64e2a6c' for key 'phpbb_sessions.PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('f4777d54c41f49302148b9f2a64e2a6c', -1, 1766047866, 1766047866, 'd849d8d7', -4, 0, 0)

Line : 187
File : sessions.php