User blog comment:MisterWoodhouse/Pausing UCP migrations to resolve some critical blockers/@comment-33695797-20200917041418/@comment-1869454-20200917072245

Fandom makes use of Mediawiki's software. There are quite a number of interfaces available with which to edit Mediawiki-based articles: most of them can be seen listed out here.

So-called "legacy" Fandom wikis (such as this one, community.fandom.com) run on Mediawiki 1.19 (from 2012), and offer the VisualEditor plus the 2006 JavaScript-based editor. Of the two, the 2006 editor is commonly preferred by regular users, as it allows direct wikitext editing, while offering speed & stability - the VisualEditor is slow, a little bit buggy, and simply cannot be used to finetune pages to the same degree.

However, the 2006 editor was removed by MediaWiki update 1.32, and Fandom wikis that undergo the "UCP" migration are now based on MediaWiki 1.33 (from 2019 - much more current, but not the latest). Although there are quite a number of other editing interfaces that can continue to be used with this more recent version, Fandom has thus far opted to only make the VisualEditor editor available on their UCP platform.

The 2017 wikitext editor is an addon of the VisualEditor. Although it allows direct wikitext editing (like the 2006 editor does), it carries most of the same performance issues of the VE it runs through - and introduces some serious new bugs as well.

Obviously this hasn't gone down well with those users forced onto the UCP, leading to more than a couple of complaints about the matter. So the plan is to enable access to the 2010 editor as well, in the hope that it'll serve as a better replacement to the 2006 editor.