Recently upgraded to the latest version of Firefox 70.0 and received the "Firefox is up to date" message with no issues. However, I am experiencing difficulties as around 70% of the web pages are not displaying properly.
The browser only shows some parts of the content while hiding crucial information on numerous pages. For instance, pages with broadcast video players display everything except for the actual videos.
On certain pages, the navigation menu is concealed, yet it is still possible to access them by copying the URL and opening it in Chrome, then clicking on a specific menu item, recopying the URL, and reopening it in Firefox.
Unfortunately, some important websites have become completely unusable since I can only view colors and text without any functionality whatsoever.
It appears that Firefox has implemented a significant security change causing many sites utilizing JavaScript in their code to malfunction.
All affected pages display the same error message: NS_ERROR_FILE_NOT_FOUND