translation edit goes to "access denied"

I have a multilingual site with a custom theme and I need to start adding in the other languages. All the translation components seem to be in place, and I was able to set up the menu, but when I try to create a translation of a node, I get "access denied". I've gone through several postings to see if I can find something that solves my problem, but no luck.

The translation tab is there for the node. The language is set to English, not "language neutral". I've checked permissions. I'm the superuser and have access to everything. There are a few different Translation components already installed (It's a pre-existing site that I'm modifying) I see the Translation Management Core components, Entity Translation is in there, even Google translator, Microsoft translator, and Local translator. I've updated all modules, the problem persists.

I tried turning off Entity to see if it was clashing with something, but no luck. I also double checked the site's live version, and the problem was there before I even touched the code, so likely nothing that I've done in my time on the site.

In the content types, I've tried different settings under Multilingual, but nothing makes a difference. Right now, most have "set current language as default" checked and extended language support set to Normal. I tried Extended too, with no luck. Under Content Type Publishing options I've tried enabled, enabled, with translation, and with field translation.

Nothing seems to make a difference. Maybe there's some arcane combination of things I need to do? I can go into the translation tab. But any time I click on edit to add, for example, a French translation. It just goes to "access denied"