One of the suggestion from Ultimate Security Checker was
It's better to turn off the file editor for plugins and themes in WordPress admin.
I googled how to do this and the suggestion was to add the line
However, when I did this, the dropdown menu in both the Dashboard tab and the Plugins tab stopped working. This meant I wasn't able to get to the automatic updates pages for plugins or WordPress.
Does anyone have an alternate method of turning off the file editor that doesn't have this side effect?