This Elastic installation has strict security requirements enabled that your current browser does not meet

As you said in your original message @nkf_123 disabling Kibana's strict CSP mode does open you up to unsafe scripting practices. You can enable these options if you're comfortable with the risk.

Alternatively I would look at your proxy settings to see if they need to be tweaked. There is an example in this thread.

I also assume you're not embedding the Kibana dashboard in a web application, which can also give you CSP issues if misconfigured?

Hope that helps!