Already added your phone number and can’t login? Here is a fix available you can try to get into the Call of Duty: Modern Warfare 2 Open Beta.
How to Fix
Go to Steam’s settings in the top left of the client.
Click on “Web Browser” and then click “Delete Web Browser Data”
This Call of Duty: Modern Warfare 2 guide was originally published by Brady. All credits for the text and images goes to him!