I get that problem with emojis too - I’ve got no idea why but sometimes they just don’t appear! I’ve been replacing mine with their HTML entities for as long as I can remember but I know that not everybody will know how to do this.

Does the red error say something about a malformed URL? It’s another one that I see every now and again but there’s never been an obvious reason for it. I normally just blame the server and try again later after it’s corrected itself although sometimes it just stays broken. Perhaps one day it will happen and there will be an obvious reason for it.