phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '9c9ebf85f5829dd8d78b076e33f621c9' 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 ('9c9ebf85f5829dd8d78b076e33f621c9', -1, 1498299599, 1498299599, '36505992', 4, 0, 0)

Line : 187
File : sessions.php