phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '6bf2a1cdd27b4a18984bf512f652e96e' 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 ('6bf2a1cdd27b4a18984bf512f652e96e', -1, 1513108782, 1513108782, '369133fa', 8, 0, 0)

Line : 187
File : sessions.php