phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'ac38fbabc3e26c15f2ab680d466d4487' 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 ('ac38fbabc3e26c15f2ab680d466d4487', -1, 1766024159, 1766024159, 'd849d8d7', -4, 0, 0)

Line : 187
File : sessions.php