Saw a post similar to my issue from about a year ago, but it didn't say how the fix was actually completed. Basically, when I click on the link button (or really any button that pops up a secondary settings screen - images, video, tables, etc.) on the visual editor I get a 403 error. I recently tightened security, so I know it's being caused by a permissions error.
The post I saw about this said it wasn't about chmod permissions, but had something to do with the Apache vhost. Is that what I should be looking at and how do I do that? I know this is probably really simple and am fairly embarrassed that I don't know what I'm looking for here. Any help would be greatly appreciated.