Visual editor vanished since last time I blogged

I didn’t see any recent discussions on this (the only ones I saw were months old, before 4.2 came out).

My visual editor is just gone. Click on the tab and it’s a plain blank white area. I can still access the text editor. Had a heck of a time tonight posting a blog by coding it and then comparing the preview image. Brought back memories of 1999…

I THINK this problem started with the 4.2.2 upgrade, but I’m not entirely sure. I’ve been away from blogging for a few weeks, so not 100% sure if the problems started then or a couple of weeks earlier.

I’ve search EVERYWHERE for other people with the same issue, and there seem to be many. However, I haven’t found a solution that has worked so far (and some of them, I simply don’t understand).

I have cleared my blog’s cache.
I have cleared my browser cache.
I have created a new admin profile and logged in there.
I have checked to make sure the box that says “Disable the visual editor when writing” is NOT checked.
I have put in some code into the “wp-config” file that someone said was supposed to fix it (it didn’t).
I have logged on/off, tried different browsers, different computers…I even logged into my dashboard on my Android (which I had never tried before,).

Nada, nothing, zilch. No visual editor.

Can ANYONE help?

I am using Twenty-Ten theme (updated it AFTER this problem started, hoping that would solve it, but it didn’t either.

Thanks,
Lynn