AMAZING! Thank you! That was the problem. I didn’t even think of trying a different browser 
I take it back — I have it downloaded. Have set up the font folder in the /Library/Application Support/Adobe/ only nothing is available for me to view in TextPreview.
I can copy/paste into the window but can’t select a font or amend size or anything — any idea what I might be doing wrong now?!
You can define the watch folder in the preferences. And after you made that folder, you need to restart the app.