phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'd4fcd8f6ff170e244aea8432cdd6fbc6' 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 ('d4fcd8f6ff170e244aea8432cdd6fbc6', -1, 1771211666, 1771211666, 'd849d8a7', 9, 0, 0)

Line : 187
File : sessions.php