phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '79981fb636f078bccdf7a32e192fc9c3' for key 'PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('79981fb636f078bccdf7a32e192fc9c3', -1, 1781004511, 1781004511, 'd849d967', -4, 0, 0)

Line : 187
File : sessions.php