phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'f40a6f36395bc09ddf1cc63348f0aefc' for key 1

INSERT INTO phpbb2_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('f40a6f36395bc09ddf1cc63348f0aefc', -1, 1492934804, 1492934804, '36503602', 21, 0, 0)

Line : 187
File : sessions.php