Encountering a - initializeInlineEditors, error upon opening a Page with a text widget

What are the rules on the firewall? Are you using any custom headers for content security policy? If yes, make sure to always whitelist the Kentico administration parent site using the frame-ancestors policy.
Have you tried applying the latest hotfix too?

Hi Juraj,

Thanks for answering.

1) About the rules on the firewall, I need to check on with our network guys about it. 2) Custom headers, I'm pretty sure we are not using any custom headers. 3) What do you mean about the whitelist the Kentico administration? Is it our CMS site? 4) About the hotfix, we only have the 12.0.35 not the latest I suppose.

Chris

I asked about custom headers because as you can see in the documentation you need to whiteliste/exclude the Kentico admin URLs - this means the URLs from the Kentico CMS application (when using MVC, you have two apps - the MVC front end app and the Kentico admin app).

If you are using any custom scripts, jQuery, Bootstrap, etc. I would try disabling them in your MVC app to see if it makes any difference. Note that the preview mode, page builder loads the code from the MVC app inside Kentico - so the issue is in 95% of cases in the MVC app code, not in Kentico itself.

Thanks for replying.

So, I got word from our network guys and everything looks fine. Any traffic is allowed to pass through, not blockage happening. Is there something else that I can do?

Here is the Javascript error.

CSP Response Headers, it contains both the ADMIN and SITE domains.

This is really strange. It is hard to tell since I do not know your MVC code. Would it be possible to install the Dancing Goat MVC sample project and reproduce the issue there? And then let us know the code and steps how to reproduce the issue? Thank you!