phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry 'a70f38a878d1a809173f75b5d489facf' 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 ('a70f38a878d1a809173f75b5d489facf', -1, 1771010358, 1771010358, 'd849d88a', -4, 0, 0)

Line : 187
File : sessions.php