phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '6723a8f7c065d652d919624f12ed11d1' 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 ('6723a8f7c065d652d919624f12ed11d1', -1, 1534401176, 1534401176, '36e12602', -9, 0, 0)

Line : 187
File : sessions.php