For anyone who is experiencing the same issue, this question was answered through a ticket.
The issue is that the English language pack is either disabled or does not exist in the system.
First check if you already have the English installed and if it's simply in the disabled status. To do that navigate to Settings->Administration->Languages. If yes then change the status to enabled.
If it is not in the list, you will need to download the language pack from Microsoft site http://www.microsoft.com/en-us/download/details.aspx?id=40340
You can also find the installation instruction there.