phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '997399ea2e9450e4ef9957b97f5542ed' 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 ('997399ea2e9450e4ef9957b97f5542ed', -1, 1464190708, 1464190708, '36e138fa', -1, 0, 0)

Line : 187
File : sessions.php