phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'af0776e72ef8d1d77f9a9328470e9c64' 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 ('af0776e72ef8d1d77f9a9328470e9c64', -1, 1770424168, 1770424168, 'd849d897', -4, 0, 0)

Line : 187
File : sessions.php