visual editor missing in WP 4.9.4

I have read all the other posts about the missing visual editor problem, and tried everything: clearing cache, deactivating plugins, concatenate scripts, checked user settings, created a new user, echecked console for errors, tried different browsers, and a couple others… and still no luck. The only thing I haven’t done is completely deactivated my theme and some of the essential plugins because it’s a production site and I can’t.

When I can I will try to take a snapshot of the production machine and put in in a dev environment where I can really mess around. I read about the Health Check plugin but am afraid to install it on production, too, because some reviews indicated it crashed their sites and ruined their database. So I’ll have to try that on dev first, as well.

Any other ideas on how to fix it? We were hacked back in December and I wonder if this could have anything to do with it? All the website files are restored from clean installs but the database is still the same one.

Any other ideas on how to make the visual editor reappear?

Thanks for any other leads you can give!