phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '4d7b54e73a4fb66a77f1d30e406d49d5' 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 ('4d7b54e73a4fb66a77f1d30e406d49d5', -1, 1766018806, 1766018806, 'd849d8d7', -4, 0, 0)

Line : 187
File : sessions.php