As you can see when you are starting a new topic the editor looks normal, but in mine it looks like below.
Hi @djdubuque,
This kind of problem is usually caused by either a conflict with your theme or with other plugins.
Please try to deactivate plugins one by one and check after each deactivation. Please keep the cache plugin deactivated during this testing process.
Hi @djdubuque,
There maybe two issue:
1. We found conflict with Mesmerize Companion plugin, this plugin stops loading of editor JS files, it does hard affection and conflicts. We recommend contact to this plugin support and let them know that this plugin stops loading of tinymce.min.js file.
2. make sure the Disable Visual Editor option is unchecked in Dashboard > Users > Your Profile admin page.
I had my site worked on by a Freelancer and they were able to manipulate the site to show the editor in the forums. What they did was setup a script to deactivate the problem plugins when a member logs in and the editor will show up in the forums. Once they logout the script re-activates the problem plugins. This is so that the theme displays correctly.
I've tested this from more than one account logged in at one time and it seems to work without issues. I'll keep you posted if anything unusual happens.