phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '1728c399f3ff348f6930c9e07bff8bc6' 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 ('1728c399f3ff348f6930c9e07bff8bc6', -1, 1781069184, 1781069184, 'd849d8ae', 0, 0, 0)

Line : 187
File : sessions.php