Hi Rafalp,
I know this is not your problem, but before I go through all the code in misago javascript I would like to ask, if you have experience with Revolution slider + misago, or on top of your head know what might be causing issues here.
The slider works fine when I remove misago's vendor.js file. When both are on misago works just fine, but the slider is blank.
A copy of the relevant rev slider files are available here:
revolutioncdn-themepunchgbr.netdna-ssl.com/wp-content/cache/busting/1/wp-content/plugins/essential-grid/public/assets/css/settings-2.2.4.css
revolutioncdn-themepunchgbr.netdna-ssl.com/wp-content/cache/busting/1/wp-includes/js/jquery/jquery-1.12.4.js
revolutioncdn-themepunchgbr.netdna-ssl.com/wp-content/cache/busting/1/wp-includes/js/jquery/jquery-migrate.min-1.4.1.js
revolutioncdn-themepunchgbr.netdna-ssl.com/wp-content/cache/busting/1/wp-content/plugins/revslider/public/assets/js/jquery.themepunch.revolution.min-5.4.8.js
revolution.themepunch.com/wp-json/oembed/1.0/embed?url=https%3A%2F%2Frevolution.themepunch.com%2Fjquery-news-rotator%2F
revolution.themepunch.com/wp-json/oembed/1.0/embed?url=https%3A%2F%2Frevolution.themepunch.com%2Fjquery-news-rotator%2F&format=xml
revolutioncdn-themepunchgbr.netdna-ssl.com/wp-content/cache/busting/1/wp-content/plugins/essential-grid/public/assets/js/jquery.themepunch.tools.min-2.2.4.js