So I can’t preview my story on writer’s portal at all, I’ve tried refreshing and I’ve logged out then logged on and even restarted my laptop, but this keeps popping up.
Mine does that sometimes if my internet is being slow.
I just have to give it a bit then go back when it does it to me. 
Really? Mine has been happening for like 3 days already 
Oh I have never had it happen that much! 
I have that problem too only for me the preview window is black and it says loading story but the story never shows. I just made a topic on this too, let’s hope they can fix it.
Okay, so when it shows those numbers like that it’s downloading assets. Wait for that to finish, when it disappears, close the preview window, reopen it. Now, Hover over a line (from your script), and then click preview.
It can’t be fixed, you’ll have to switch computers or browsers. I’ve been having this problem since the beginning of this year and episode doesn’t help at all