I've been searching around trying to establish whether I have missed something however my MediaWiki with VisualEditor doesn't appear to match the editor from the Sandbox page. For the most part it is all there, but the 'Insert' drop down looks to be missing options such as 'Code Block'. I gather it may be down to a plugin that needs to be added but there doesn't appear to be any documentation as to how this was created.
Any help would be appreciated!