This should be fixed in the next build. This occurred when upgrading while the add-on was disabled, because VaultWiki needs the add-on to be enabled in order to perform certain upgrade tasks (such as updating the search index). The upgrade was designed to detect this situation and re-enable the add-on automatically; however, it did not do so in a way that caused the needed add-on data caches to be rebuilt. In the next build, we add this intermediate step.