phpBB : Critical Error

Error creating new session

DEBUG MODE

SQL Error : 1062 Duplicate entry '6b51bf4bcaf3b59f2dd72db90518a9f7' 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 ('6b51bf4bcaf3b59f2dd72db90518a9f7', -1, 1766771094, 1766771094, 'd849d82e', -4, 0, 0)

Line : 187
File : sessions.php