Like most people, I have to agree, this add-on opens a blank Page. If the other commenter is right and I would have to disable ALL legacy add-ons for this to work, well, not going to happen in the near future...

Useless, the button does nothing.

It's not working.

Do nothing after click

blank page new tab why?

Does what it says. Finds all files including js, jpg, gif, css, etc.
I had one problem after installing, just like Не работает writes: it opened only empty tabs. After removing a legacy extension, it worked. I don't remember which extension it was, but it was a legacy extension.
So if it doesn't work, you may try disabling legacy extensions.

All what this addons do - open empty tabs. I try a difrent version of Firefox - no result.
Link Gopher is better.

Please update support for new versions FF (55+)