I have been really thankful for this add-on for a long time. Yes there's a little hick up right now, and it did not work to create a completely new Profile in Firefox 57.

However I found a workaround so I can use this til it's fixed.
It seems to only work with 1 saving/settings/site. Then I have to restart FF, and make a new setting to a site.
Hope this helps anyone else.

ThanX a million for this add-on @Baris Derin! Can't live without it!