phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '81256e6ab7db062af6362cf3abd28e73' 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 ('81256e6ab7db062af6362cf3abd28e73', -1, 1768000675, 1768000675, 'd849d8a2', -4, 0, 0)

Line : 187
File : sessions.php