Running r85439 of MediaWiki and the Duplicator extension, an error is thrown when viewing any page:
Notice: Undefined property: SkinMonoBook::$mTitle in /htdocs/example_com/p/extensions/Duplicator/Duplicator.php on line 46
Fatal error: Call to a member function getNamespace() on a non-object in /htdocs/example_com/p/extensions/Duplicator/Duplicator.php on line 46
This seems like an issue in the Duplicator extension.
Version: unspecified
Severity: enhancement