Line 6 now requires you to open a ticket to get direct support (or call them):

http://line6.com/support/tickets/

And choose the Contact Technical Support link.

To troubleshoot your problem here you will need to provide more information, such as:

- Which version of Windows or OS/X are you using? 32-bit or 64-bit?

- Are you connected directly to the computer or through a USB hub? (you need to connect directly)

- Do you have the latest version of Line 6 Monkey?   http://line6.com/software/?submit=Show&name=Line+6+Monkey

- Do you have your 1/4" jack plugged in and the power turned on on your JTV?

- Is your battery fully charged?

- What error messages are you seeing or what is the problem step during the update?

Edit: Additional useful info here: http://line6.com/support/docs/DOC-2680