A huge amount of articles just give me "There is currently no text in this page. You can search for this page title in other pages, search the related logs, or create this page." after upgrading. Hit "Random page" and you'll likely end up on an article that's fine.
If you had an account and hit "Edit" while logged in, you'd see "The revision #0 of the page named "Main page" does not exist.
This is usually caused by following an outdated history link to a page that has been deleted. Details can be found in the deletion log."
Of course, the page hasn't been deleted so there's nothing there. View "History" and you get it telling you that there are "x pages" of revisions but they will not display. I have since used pretty much every maintenance script and nothing works.
Inside the DB, broken articles and working articles are all seemingly formatted in the same way. The text exists in the DB for broken ones just as it does in working ones. The maintenance script to check for pages tells me the pages exist. They just won't show up on the wiki itself.
I can revert to 1.32 with a backed up DB just fine, but attempting to upgrade fails every time in the same way.
I will note that I'm pretty sure all of the articles that don't work were modified more recently than the ones that do work. I'm pretty sure I narrowed the broken articles down to a certain point, in that articles from before that point are all fine. Like I said, though, the article structure seems to be the same in the DB for ones that do and don't work.