You can run the registry fix tool just in case it solves the problem but I am very skeptical that it will. It is in the tools submenu.

There is no such NVDA setting. To clarify, you discussed the problem on another list and you didn't report that unknown is spoken when you try to read a document. Your description of what you see indicates that no document window is shown. You say that using a very old version of Firefox, version 52.x, you can see the document.

I don't know what is causing the problem, but I don't think it is an NVDA problem. Do you have a sighted person who can tell you if he/she sees the document window and if it looks different than it should?

You can run the registry fix tool just in case it solves the problem but I don't think it will. It is in the tools submenu.

Also, you reported other problems with your system such as two or three error messages on boot up. You need to make the list aware of those messages and what happens when you try to reinstall a JAWS demo. One or more of the problems may be causing the problem you are having with Firefox. Firefox has undergone significant internal changes since 52.x and one or more of the errors may affect it.

Gene