phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a9e0eb856825a31ba03e27aea09aa26b' 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 ('a9e0eb856825a31ba03e27aea09aa26b', -1, 1510972428, 1510972428, '36e07943', -4, 0, 0)

Line : 187
File : sessions.php