phpBB : Critical Error

Error creating new sessions

DEBUG MODE

SQL Error : 1062 Duplicate entry '1b4677cf6b789f102247ed2d73b85cbe' for key 1

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('1b4677cf6b789f102247ed2d73b85cbe', -1, 1511468258, 1511468258, '36e13959', 2, 0, 0)

Line : 187
File : sessions.php