All is correct, you don't have any reason to wary. We've updated wpForo Persian translation file and readme.txt in wordpress.org plugin directory, they have been updated on all websites automatically too. This update was made without new version release.

As per colors.css I've already explained that this should be ignored.

https://wpforo.com/community/how-to-and-troubleshooting-2/changes-of-templates-colors-does-not-change-the-forum-colors/#post-5899

Thank you

@Robert, I have to re-visit this subject.

Let me explain, I have a test/staging forum and production.

On my test site I have for few weeks [maybe since the last update] 5 alerts from Wordfence indicating that the source and my files do not match.

like this:

Modified plugin file: wp-content/plugins/wpforo/wpf-includes/functions-installation.php

This file belongs to plugin "Forums - wpForo" version "1.3.0" and has been modified from the file that is distributed by WordPress.org for this version. Please use the link to see how the file has changed. If you have modified this file yourself, you can safely ignore this warning. If you see a lot of changed files in a plugin that have been made by the author, then try uninstalling and reinstalling the plugin to force an upgrade. Doing this is a workaround for plugin authors who don't manage their code correctly. [See our FAQ on www.wordfence.com for more info]

On my production I have none of these messages.

What is the explanation for this since both sites are up-to-data?
Wordfence suggest to remove and re-install wpForo but I'm hesitating to loose data and setups [on my test system]

Is there a way to fix it or wait and see what will be after the next updates?
If it helps, my test system is on a sub-domain and production on main domain.   

Thank you

We've added a small change (default value of some options) in functions-installation.php without releasing a new version. That's it. You can ignore this message. This doesn't worth your time. There is no security issue here.