phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a4d91860c282e8583f654ba1bcaade6e' 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 ('a4d91860c282e8583f654ba1bcaade6e', -1, 1768696579, 1768696579, 'd849d879', -4, 0, 0)

Line : 187
File : sessions.php