In your LocalSettings.php, if you configure things in the following order:
1 - require_once("$IP/extensions/UploadWizard/UploadWizard.php");
2 - require_once("$IP/extensions/TimedMediaHandler/TimedMediaHandler.php");
3 - $wgFileExtensions = array_merge( $wgFileExtensions, array( 'doc', 'docx' ) );
Then, you won't be able to use the UploadWizard *at all*. If will always fail with the following javascript error:
This wiki does not accept filenames that end in the extension ".xxx".
If you change $wgFileExtensions before requiring TimedMediaHandler.php, then it works like a charm.
MediaWiki 1.21.2
PHP 5.3.10-1ubuntu3.8 (fpm-fcgi)
MySQL 5.5.28-0ubuntu0.12.04.2
Upload Wizard (Version 1.3)
TimedMediaHandler (Version 0.3)
Version: master
Severity: minor