Rename and Target is Missing
When you rename an article, a new article is generated with the old title that redirects to the new article. However, in the wiki link cache, the target of the redirect is not saved in the redirect's row (the value is saved as 0).
This could be due to a number of reasons. The vault list could be missing the new title when the redirect is created, resulting in it not being found. The redirect could be saved but then erased on the subsequent page load.
Whatever the reason I messed around with some stuff that had been objects by reference and used a getting then setting method instead. After some more tests it seems to function correctly again.
Fixed for the next build (or so it would seem).