Board Thread:Support Requests - Designing Your Wiki/@comment-35591859-20180406160452/@comment-9605025-20180407232223

Well, VisualEditor has enough issues already. I would image it would be even worse if Wikia tried to allow wiki's to customize it. That being said, it can probably be done with JS; since that is a large portion of how VisualEditor works in the first place. Unfortunately, I cannot help you there.

Have you enabled the JS review process for your wiki? It may also just be a temporary database unavailability. That happens from time to time when they do large/significant updates.

If you have any specific changes you would like to make using CSS. I can help out as you learn how to do it.