During the development , customization and adding new plugins you're probably creating many problems. This is normal. But you should remember what have you done and revert your changes in website. So you should know better why this happens. Maybe you've installed some new plugin, enabled some new feature of other plugin, or you made some changes in your server configuration recently.

So just go back step by step and find the problem maker. It's not in wpForo so it cannot be fixed from wpForo side. Something affecting wpForo editor. I think some plugin or theme generates lots of JavaScript errors and stops all other JavaScript functions. We'd check it if the website could be online. But in your localhost it's impossible, you should find the problem maker yourself by disabling plugins other one by one. Or even changing the WordPress theme to a default one.