Configuration of the Twitter widget can be found at
In order to let people connect their account to this widget, you need a Twitter API key (https://dev.twitter.com/faq#46). Go to https://apps.twitter.com and click "Create New App". Fill in the details and for "Callback URL" only enter your domain (this cannot be left blank allthough the actual callback url is set in the script). When the App has been created, click the "Keys and Access Tokens" tab and paste the Consumer Key (api_key) and Consumer Secret (api_secret) in the configuration file (oauth.php).
This widget doesn't need write access, so you can click "modify app permissions" at Access Level, and select "Read only". Click "Update Settings" and you're ready to go.
Alternatively, if you don't want to use this widget, open
/widgets/twitter/config/oauth.php and set
'active' => false.