JSLint (prior to version 2013-03-18) throws the "ADsafe violation: Wrap the widget in a div" error when the adsafe and fragment options are set to true (they're false by default) and you pass it a fragment of HTML that is not wrapped in a div element. Here's an example:
ADsafe widgets must be wrapped in a div element. The ADsafe widget documentation states the following:
The <div> element must have an id. The id must contain only upper case ASCII letters with a trailing _ character.
In a commit on 20th March 2013, HTML, CSS and ADsafe parsing functionality was removed from JSLint. If you rely upon this functionality, you will be unable to upgrade JSLint to a version beyond that date.