phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a9b5979ef09cdc1dcdeacae3bd6b2d2a' 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 ('a9b5979ef09cdc1dcdeacae3bd6b2d2a', -1, 1768770532, 1768770532, 'd849d8ad', 1, 0, 0)

Line : 187
File : sessions.php