User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-45057330-20201222012405/@comment-1038387-20201222125645

With "new article box", did you mean the Createbox tag? That was deprecated a while back, and retired for UCP. Inputbox has the same functionality, with type=create.

With plugins, did you mean browser plugins, or dev scripts? If the latter, see this list for update statuses. Keep in mind that if you import one script that is broken, everything underneath it in the import script isn't working either.

Recent Wiki Activity isn't broken, it's gone. Walls are changed to a new format, which may take a while longer to fully convert. Your home page looks pretty bad but I don't know how it looked before so can't offer any advice there.