Title when editing imported yt video's, too long
80 is maximum allowed size at the moment. Video with longer title can be imported but if you try to edit it, as you have noticed, you will see the error message.
Just make the title shorter and you can manually copy-paste the title into a lesson text if you prefer. It's not that often that videos have 80+ characters in title.
I don't disagree with the advice, but it does happen often that a title is longer. I just imported a small article from yle uutiset which had the same issue. Mostly it happens with youtube (my experience: YMMV). Anyway, I will see if I can make it work that way.