Cannot post a question and other issues – multisite installation

Hi,
I have already solved one issue – that JS didn’t work and console showed me that “getUserSetting” is not a function – by calling “utils.js” (with wp_enqueue_script) before calling the plugins.
Now I have other issues:

1. The “Insert image” button does not work and even worse –
2. when submitting the question it just reloads the page and the question does not enter the database.
   Right now I can only add questions/answers from the “settings” but not from the UI.

There are no error messages in the console.
P.S. I am using a multi-site installation with WordPress 4.9.1.