On an example of a page from this site.
After opening dev tools all elements in their places.
If i’m clicking on HEAD element in dev tools and after that reloading page then all elements inside HTML are disappearing.
The problem is not always reproduced.
On some sites such a problem appears after reloading page after clicking on arbitrary elements
A very similar problem was fixed recently and the fix was made available in Firefox Nightly (62), Firefox Developer Edition and Beta (61) and backported to ESR60 too.
Here is the bugzilla ticket where the fix was made: https://bugzilla.mozilla.org/show_bug.cgi?id=1460223
@vanhun219 Do you mind testing again with one of these browser versions and checking that this was indeed fixed?
My recent update to 60.0.1 causes this to happen to me too on certain (non-public facing) sites
