Pinterest via Google Image will not show even in safe mode

[ttggzz]

Note: see addendum after links below...

Hello, I started a fresh untouched FFx profile to test an earlier problem, just tried Pinterest in it [via Google Image search] and it loaded with images no problem. In my main FFx profile, images on Pinterest suddenly stopped some months back. Specifically, it is when I do a Google Image search for something, then go to a pinterest image from that page. The entire page is blank, even in safe mode! Any idea where I could start with something like this?

On another note, in searching for answers I found this script for Greasemonkey, I can load the "categories" Pinterest page as suggested no problem.

I installed this script:
https://greasyfork.org/en/scripts/6325- ... gistration
via these instructions:
https://www.ghacks.net/2015/04/29/unlim ... istration/
and can see this page:
https://www.pinterest.com/categories/
and can do searches from it

example google image search:
https://www.google.com/search?client=fi ... Ck0#imgrc=_

this Pinterest link from that page is completely blank:
https://www.pinterest.com/pin/554998354051747297/

Addendum: I have been using Google Image search since forever without being signed in. I just signed in as an experiment and after doing an image search went to a Pinterest page. Sure enough, they want me to "create an account" and use Pinterest via my google account. Whether that is why I can't see images I don't know and I'm not going to find out by creating an account.

Now that I have the above script installed and can look at Pinterest without the "create account/login" blocking access I am going to start investigating doing image searches directly from the Pinterest "categories" page. Still would like to know why the images stopped showing via Google Image, is it because I am not signed in?
thanks

[ttggzz]

Well, I messed with my prefs.js file, changed it to prefs.js.bak then restarted. I messed up the trip back, I believe I should have deleted the newly created prefs.js file then renamed prefs.js.bak to prefs.js. Anyway, it's gone, and... pinterest images will now display via links in Google Image search. So, it was something in my prefs.js

Meanwhile, along with all this, firefox has been running really slow, and with more than one profile open, one will sometimes hang and then crash. And video is stuttering. I thought it was because I had a huge 15 window session open with hundreds of tabs [for weeks], but that is now closed and same behavior with just a few tabs open.