I'm getting "Undefined variable wgCategorySuggestCloud in C:\xampp\htdocs\wiki\extensions\Categorize\Categorize.hooks.php on line 60". If I comment it out, anything works well. I also installed "SelectCategoryTagCloud" but still the same error. Furthermore it would be nice if you could add an option to still show the [Category: ...] in the MediaWiki-Text.