phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '8400b6ba1b8d9a9a0ef3a249f1738148' 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 ('8400b6ba1b8d9a9a0ef3a249f1738148', -1, 1770979785, 1770979785, 'd849d809', -4, 0, 0)

Line : 187
File : sessions.php