phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '78a6e291a75e289aa1be0604bd2ed27c' for key 'phpbb_sessions.PRIMARY'

INSERT INTO phpbb_sessions (session_id, session_user_id, session_start, session_time, session_ip, session_page, session_logged_in, session_admin) VALUES ('78a6e291a75e289aa1be0604bd2ed27c', -1, 1771210853, 1771210853, 'd849d8a7', -9, 0, 0)

Line : 187
File : sessions.php