VaultWiki is not currently compatible with vBulletin 4.1.4. They changed the editor in vBulletin. Any mods that use or extend the editor won't work anymore and will cause errors. I don't know why they didn't mention this in the announcement for the version.
Since you already upgraded vBulletin, you will have to disable VaultWiki until a patch is released.
As I've mentioned in the many duplicate bug reports on this issue, we're working on the patch with compatibility for the new editor, but have been slowed down by bugs in the new editor itself.