again and again at any attempt to upgrade my bought product Nis 2012 to Nis 2013 I get error 8506.421 !!
despite three contacts with symantec technicians on tchat who promise me a patch to solve the issue no other solution :
i have had to remove all norton products (with norton removal tools) and upload again my older version of Nis (2012) ; to be noticed that the problem occurs both with windows 7 and windows xp no matter that another antivir is installed or not on the computer ; any time we try to upgrade to the new version the program does not work ; thanks anyway to symantec to have given me a product extent validity of three months for the inconveniences ; but i do not still run the latest bought version !
still thus waiting for the miracle patch !