Due to changes in the use of the widgets and policies. The Blueprint Theme for Lightspeed no longer supports the Twitter and Facebook widget. The functionality and settings have been taken out at the last update of the Theme.
If you've activated the Theme Editor, you no longer receive these updates. However in this case it's not a problem. You can still use it as it is, without harm.
When you want to publish a Twitter feed on your website you can still do so by using an Iframe. Go to the following website and configure your Iframe:
Copy the code into the content area of your homepage and save the page. The feed should now be displayed on the homepage at the position where your homepage content should appear.