I've noticed quite a few people with this exact mistake in their app:
QuoteThis man is... Built with thick
Notice the "is... Built".
What happens is that people, I think, are copy pasting a description they wrote offline, which is great. However, the editor only seems to take a certain amount of characters before it freaks out. So, people just pick back up where it left off, however, you get the above error in random spots in the middle of your description.
It's easy to fix, and I personally fix the ones I see, however, if you can avoid it in the first place, great! One way would be to just review your app before submitting it if you typically do it offline then copy paste.
Also, remember that .i is your friend. If you type .i on a blank line in the editor, it will format it for you.