phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '3dd7a7714e5ba674f0db6a37dbf5b6eb' 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 ('3dd7a7714e5ba674f0db6a37dbf5b6eb', -1, 1464487939, 1464487939, '36a22d9d', -9, 0, 0)

Line : 187
File : sessions.php