Error 120 typically indicates an issue with your account/subscription commonly described as:

1. You are trying to play a game that may not be included in your package (unless you have the Unlimited pack)

2. You may not be actively subscribed to a Games on Demand package. Use the instructions below to verify your account info:

Goto Verizon.net and login, then click "Manage Broadband essentials and extras" on the left menu, you will see your active services in the middle of the page.

Recently the Error 120 has become a temporary login problem, to resolve this, use the link below for instructions to reset your Web Browser cache.
1. Internet Explorer
2. Mozilla Firefox