phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1a64d97a1b6c7a91a14a2a4a7b39a4cc' 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 ('1a64d97a1b6c7a91a14a2a4a7b39a4cc', -1, 1768573975, 1768573975, 'd849d834', -4, 0, 0)

Line : 187
File : sessions.php